FORESTRY
SD
445.9
&₁2
Elä
ill
2188
The Northern Bob-White's
Winter Territory
BY PAUL L. ERRINGTON AND F. N. HAMErstrom, Jr.
AGRICULTURAL EXPERIMENT STATION
IOWA STATE COLLEGE OF AGRICULTURE
AND MECHANIC ARTS
R. E. BUCHANAN, Director
ENTOMOLOGY AND ECONOMIC ZOOLOGY SECTION

AGRICULTURE
TOWA STATE COLLEGE OF
SCIENCE
WITH
PRACTICE
MECHANIGAR'S
RESEARCH BULLETIN 201
AMES, IOWA
JUNE, 1936
1
1
!om
JERARIS
*#
ļ
I
t
1
!
1
:
:
•·
:

4
.
Q
June, 1936
79
The Northern Bob-White's
Winter Territory
Research Bulletin 201
BY PAUL L. ERRINGTON AND F. N. HAMERSTROM, JR.
AGRICULTURAL EXPERIMENT STATION
IOWA STATE COLLEGE OF AGRICULTURE
AND MECHANIC ARTS
R. E. BUCHANAN, Director
AMES, IOWA
ENTOMOLOGY AND ECONOMIC ZOOLOGY SECTION
.....
302
Forestry
JJ
Foreword
Part I. Introductory remarks and technique
Carrying capacity: Definition and discussion
. Measurement of winter carrying capacity for bob-
white
CONTENTS
Winter mobility and behavior of bob-white popula-
tions .
Composition of the bob-white covey
Direct enumeration census techniques for bob-white.
Technique of track counting
Part II. Survival data
Flush counts .
Counts with the aid of rests and roosts
Interpretation of census data
Technique of tracing mortality.
Mortality from poaching
M
•
MU
Evaluation of wintering data
Survival data first class
second class
Survival data
Survival data third class
Survival data fourth class
Survival data-emergency territories.
Survival data fortuitous or built-up territories.
Survival data from large areas
Banding results compared with observational census
data
•
•
•
Page
304
305
307
310
312
314
317
319
323
324
326
328
332
333
333
334
339
345
348
355
357
360
364
303
T
Page
Part III. Analysis of carrying capacity
366
Uniformity of winter carrying capacity .
366
Seasonal reduction of bob-white population surpluses 367
Predation and carrying capacity
372
Compensatory pressure of predation on bob-white
population surplus
"Buffer" populations and bob-white losses from winter
predation
Food and carrying capacity
Cover and carrying capacity
Relation of carrying capacity and cover.
Territory and carrying capacity
Biological application of population vulnerability
•
Management and its objectives
Integration of ends in land use
Management of bob-white food
Management of cover.
Predator control
Summary
References cited
Part IV. Management of the bob-white's winter territory 405
405
407
409
412
416
420
424
427
434
438
441
•
·
Management of shooting
Population estimates.
Experimentation on the land
Concluding remarks on management
374
376
380
383
392
398
402
304

FOREWORD
This bulletin is presented for whatever utility
it may have from the standpoint of conservation
and wildlife management. The institutions and
persons cooperating and financing the concur-
rent Wisconsin and Iowa researches on bob-
whites have been strongly motivated by the
hope that the findings may have substantial
practical application as well as value to pure
science.
1. The Wisconsin Quail Investigation from 1929 to 1932 was
established at the University of Wisconsin by the Sporting Arms
and Ammunition Manufacturers' Institute and the U. S. Biological
Survey; the Iowa wildlife research program, 1932 to 1935, at Iowa
State College, by the College and the Iowa Fish and Game Com-
mission, cooperatively, with J. N. ("Ding") Darling financially
contributing.

305
The Northern Bob-White's
Winter Territory 2
BY PAUL L. ERRINGTON AND F. N. HAMERSTROM, JR.
PART I. INTRODUCTORY REMARKS
AND TECHNIQUE
This bulletin attempts to bring up to date our knowledge of
individual covey ranges or wintering territories of the bob-
white quail [Colinus virginianus virginianus (Linn.)] (Fig. 1.)
It is based upon all of the pertinent and reliable data upon
the subject at hand, of whatever origin and whatever degree
of previous publication. Pertinence and reliability constitute
the sole criteria by which we have attempted to judge the eligi-
bility of data used, whether the data support our principal con-
clusions or not.
While based chiefly upon Iowa and Wisconsin studies, and
intended particularly as an aid to bob-white management³ in
those two states, this technical presentation is not confined in
its scope by state lines. Very conceivably, the conclusions ar-
rived at may apply to the North-central States region as a
whole, or roughly to the northwest portion of the bob-white's
2. Project 329 of the Iowa Agricultural Experiment Station.
3. Management of a wild species usually means the encouragement of the species
under conditions as nearly natural as possible; it lays emphasis upon environmental
control rather than legal protection or artificial propagation.
Fig. 1. Bob-white covey feeding. Courtesy of Milton F. Hulburt.
306
natural and naturally extended geographic range.
Management of wintering territory, under conditions repre-
sentative of the North-central States, is a large part of a com-
plete program of management for the bob-white. It is true that
the direct toll taken by man, as in connection with hunting,
needs a certain amount of regulation, and it may be that greater
management emphasis needs to be placed upon the maintenance
or improvement of nesting conditions. Management may at
times be forced to cope with novel, though drastic, emergencies.
For all of the latter, however, winter in the northern part of the
bob-white's range seems to be the one supremely critical period
in the life equation of the species, and winter survival cannot
exceed ability of environment to accommodate population.
Winter is a period of increased crisis to bob-white, con-
spicuously because of emergencies associated with cold and
snow. Less spectacular, is the distinct change in habitability
of the environment for bob-white which is coincident with the
annual transition from autumn to winter conditions of vege-
tation.

With the advent of winter, a bob-white population adjust-
ment is typically necessary, even though there be no snow. The
adjustment or "fall shuffle" [Leopold (46) pp., 49-51] takes
place in response to the wholesale seasonal shrinkage of quail-
habitable environment brought about by the withering of
herbaceous vegetation and the loss of leaves of deciduous woods
and brush. It is unquestionably influenced also by changes in
the food supply, occurring naturally or through the agency of
man.
Prior to these regular autumnal changes in bob-white en-
vironment, a given tract of land has a capacity to accommodate
a much greater number of birds. In summer, food is usually
abundant and well distributed, concealment cover may be found
in greater or less quantity nearly everywhere, and the habita-
bility of the land for quail is doubtless high enough to take care
of the adult population plus substantial increases of young.
Then, as winter comes, the bob-white population may find
itself in an environment which has out-shrunk it. Consider-
able acreages of formerly attractive habitat may now be plowed
ground. Other lands, though unplowed, may have plant
growths trampled and pastured flat, or may be swept clean by
burning. Even when unmolested by man, many heavy brush
and weed patches, formerly offering quail cover almost impene-
trable to attacking enemies, may stand frost-stripped and open.
By late fall, the total plant growth capable of serving as
effective escape cover may be confined to a few gullies or wood-
lots or watercourses, or to a few other places where vegetation
may be sufficiently dense to give the birds something to get into
307
in case of danger. Brush heaps, abandoned farm machinery,
piles of discarded woven wire, and the like, sometimes consti-
tute the bulk of the utilizable escape cover on some properties.
In brief, not a great part of any area has the quail cover on
it by winter that it had in early fall. The net habitability of the
residual escape and concealment cover is frequently further
lowered by partial or total lack of access to a suitable food sup-
ply. The winter environment may be so barren as to be quite
uninhabitable. The relation of food and cover to each other is
of primary significance in determining the adequacy of bob-
white environment.
We may readily perceive, therefore, how winter environ-
ments at their best may be inadequate to accommodate popula-
tions existing in comparative security under the more favor
able conditions of late summer and early fall. The carrying
capacity of an area for bob-white may conceivably be reduced
by half or possibly more, simply by the natural seasonal loss of
leaves from deciduous vegetation.
The acceleration of bob-white losses from predation com-
monly noted in late fall is apparently but a manifestation of
increased exposure to enemies [Errington (26)], as it corres-
ponds well with cover shrinkage and the incidence of early
snowfall. Counts made in the 1933-1934 field studies in southern
Iowa [Errington and Hamerstrom (35)] indicate a usual
fall population substantially in excess of the winter carrying
capacity of the land.
CARRYING CAPACITY: DEFINITION AND DISCUSSION
Winter carrying capacity for bob-white, as used here, was
first defined as the heaviest population that a specific environ-
ment could be expected to winter [Errington (26)].
In view of the variable interpretations put upon this concept
by almost every reader, perhaps it would be well to elaborate
upon the subject in more detail.
We admit that there may be a better term than "carrying
capacity" to express our meaning. It may be true that our
usage is not wholly correct technically. But insofar as it is
used in the absence of anything which we recognize as super-
ior, the least we can do in the interest of clearness is to try and
point out plainly what we do and do not intend it to mean.
It is especially desirable that there be a minimum of mis-
understanding in this respect, for carrying capacity is a prop-
erty of unique significance so far as bob-white wintering
environment is concerned.
Carrying capacity is not calculated on the basis of average
survival in a given covey territory from year to year. Just as
emphatically, it is not an average of survivals in all observed
308
territories for 1 year or a series of years. In its simplest form,
carrying capacity may be said to denote the upper limit of
survival possible in a given covey territory as it exists under
the most favorable conditions. This limit has now been found
to be more exact for groups of adjacent territories than for
single territories. It is calculated on the basis of survivals
recorded over a period of years for specific territories or groups
of territories [Errington (26)]. Finally, while carrying
capacity appears to be relatively constant from year to year
for a specific territory or group of territories, it is not the same
for all territories or groups of territories.
While data on average survival are certainly of value, they
do not constitute a basis for the determination of carrying
capacity as herein defined. Carrying capacity refers to a com-
paratively rigid and non-fluctuating winter survival limit
which in nature is not attained every season, but which, never-
theless, effectively delimits higher population ascendencies.
Average survival is conditioned not only by carrying capacity
at one extreme, but also by variables such as winter emer-
gencies, excessive shooting and incomplete population recov-
ery during the breeding season.
To quote from a recent popular article [Errington (28)]:
"Winter carrying capacity of quail environment may be
crudely compared to the capacity of a farm chicken coop. A
chicken coop has room for only about so many birds, and if
a poultryman has more chickens than his coop can accommo-
date, obviously he cannot get them all in. If the extra chickens.
leave the premises and find security in some other poultryman's
coop, which doesn't happen to be filled up, it may make little
difference to them. In the event of visits by predators, the
chickens exposed outside will suffer, not the ones secure in
coops. Depredations may continue until all of the chickens out-
side of the coops have been killed or driven away; those prop-
erly housed, however, will still be reasonably safe.
"To be sure, a quail wintering territory has not as sharply
defined boundaries as a chicken coop, but the analogy is not
far fetched. A quail covey range or territory has a combination
of food resources and escape cover suitable for an approxi-
mately constant number of birds. As chicken coops are built in
different sizes, so covey territories occur with different carry-
ing capacities
•
"On the basis of data .
it seems that the upper sur-
vival limit is almost a fixed property, almost as inherent in the
wintering territories as capacity is in a chicken coop. Our
hypothetical poultryman could not expect to winter more
chickens than he had accommodations for, irrespective of the
number with which he might start the season
Simi-
larly, in the case of quail territories, it appears to make little
•
309
difference how many extra birds station themselves in a terri-
tory, because a limit of only about so many will get by, this
limit varying with the individual territory
""
Whatever may be the net winter survival, for one or more
specific seasons or for an average of seasons, a certain environ-
mental inflexibility seems always to operate for the reduction of
top-heavy populations to the level of carrying capacity. Starva-
tion and possibly drastic but irregular emergencies of other
sorts may reduce populations further.
In nature, the automatic limitation of winter survival to a
rather constant year to year maximum has been repeatedly
observed in the course of our field studies. Its salient manifes-
tations have been carefully measured, although many details of
its mechanism are still lamentably obscure and unyielding to
investigation. Survival data from a succession of mild and
open winters have been of particular value, in that they have
dealt rather consistently with the decline of fall over-popula-
tions to the accommodation-capacities of specific environments,
thus reducing the likelihood of confusion of the shrinkages
attending over-populations with the emergency losses due to
blizzards and to starvation precipitated by deep snows.
The definition of carrying capacity may perhaps be restated
as the level beyond which simple predation upon adult birds,
their own territorial intolerances, and their tendencies to
depart from coverts over-crowded with their own or some
other species do not permit continued maintenance of popula-
tion.
The expression "simple predation," or predation upon
adult, vigorous birds, is used in contradistinction to what we
may call "conditioned predation", the weight of which is felt
largely by semi-helpless juveniles, birds weakened by injuries,
hunger, or disease Green and Wade (38)], or those otherwise
handicapped individually.
Simple winter predation may at times be conspicuous or
unquestionably heavy, but so far as we have been able to
measure it, it is chiefly confined to that portion of the popula-
tion which is in excess of carrying capacity, seemingly
irrespective of kinds and numbers of predatory species present.
Differences in composition of predator populations studied in
connection with the quail observational areas have had no
perceptible correlation with quail mortality [Errington (26)].
Insecurity of position of the over-population seems to be the
principal factor governing the net winter loss from natural
enemies. The population in excess of carrying capacity is
dangerously exposed and hence doomed, be there few or many
predators.
Conversely, a winter bob-white population within the carry-
ing capacity of its environment shows relatively slight vulner-
310
ability to predation under the conditions studied, except when
the fitness of the population is lowered from some cause. Apart
from acceleration of predation loss rates incidental to starva-
tion, crippling from shooting, possibly disease, etc., well
situated populations were rarely observed to suffer winter
losses from wild enemies at rates exceeding 6 percent per
days. Superior bob-white winter densities-up to a bird per
4 acres and doubtless higher-were not known to suffer from
predation at proportionately higher rates, provided that the
carrying capacities of their environments were sufficiently high
to accommodate them properly.
90
MEASUREMENT OF WINTER CARRYING CAPACITY
FOR BOB-WHITE
The most reliable means of arriving at any conclusions
relative to the carrying capacity of an area is one of actual
measurement. Actual measurement necessitates three things:
(1) census work over a period of winters, preferably uninter-
rupted, (2) separation of emergency winter losses (mainly
associated with deep snow starvation and pot-shooting) from
losses due to over-population (manifested by heavy predation
on unweakened birds or often by departure of coveys), and (3)
sufficient ecological stability of environment that the carrying
capacity itself will not be subject to wide fluctuations from
winter to winter.
Census work that is worthy of the name demands of the
observer a certain specialized field technique, a knowledge of
quail behavior, and, at times, an almost insatiable thorough-
ness. It demands also a mental attitude which permits the
following up of a particular lead without bias.
We have found that passable skill in winter bob-white
census work requires a background of at least one season's
experience in the field under critical supervision and training.
In general, we have not found unguided censuses by self-taught
observers, hunters, farmers and amateur naturalists reliable.
Too often a self-taught observer's background is so permeated
by opinions and part-truths that his observations are unavoid-
ably prejudiced, even though he may be a man of vast outdoor
experience.
With some notable exceptions, cooperative quail study
projects with institutions and individuals outside of the
College have met with only indifferent success. As a rule, the
best work of this sort was done by graduate students whose
usually scant previous experience was more than counterbal-
anced by energetic interest and lack of old prejudices.
Occasionally, an older man, such as the highest type of deputy
game warden, may contribute valuable aid, if he is not more
anxious to prove his own ideas than to seek diligently and
▸
311
impartially for whatever may be true.
The splitting up of the net losses of a winter bob-white
population into the various mortality categories demands far
greater effort and field skill than making censuses, however
difficult the latter may be. Not only must carcasses or remains
of missing birds be found, but specific causes of mortality must
be ascertained in a sufficient proportion of the cases to permit
reasonably accurate conclusions. This necessitates field work
of the most intensive kind and an ability to "read sign" that has
to be patiently acquired. It may necessitate supplementary
work on species, other than bob-white, which may be visitors or
co-occupants of the observational area, particularly by means of
contemporaneous food habits studies of the principal predatory
species.
The third condition for an accurate measurement of carry-
ing capacity is fundamental environmental stability. That is to
say, the food and cover combinations should remain in some-
what similar relationships to each other from one winter to
the next. Granted that a severe storm may bring about a
temporary or even a prolonged upset of bob-white living
routine, with possibilities of terrific emergency mortality, its
effects may still be essentially measurable. The eviction of
established coveys from their territories by irregular but
devastating agricultural practices, on the other hand, presents
difficulties to correct analyses that may be insurmountable.
To illustrate: In non-glaciated south-western Wisconsin,
many farms are small enough to be within the regular range of
one or two quail coveys. As the cover conditions commonly
remain more or less unchanged for several years at a stretch,
the major environmental variations are apt to occur through
crop rotation. Nevertheless, since most of the cultivated fields
may be small and located in the valleys between wooded hills,
the actual accessibility from habitable cover may not differ
greatly, whichever field may be in corn, soybeans, small grain,
or forage crop one year or another. For many environments of
such comparative stability, carrying capacities have not been
noted to differ perceptibly over periods of several years.
Although covey wintering territories have been known to
maintain an almost incredible year to year constancy of carry-
ing capacity despite environmental changes for either better
or worse, this constancy may not be maintained if change takes
place on a large enough scale. Central Iowa farm land is nearly
all under cultivation, but, because of the large size of the fields,
only a small amount is situated near enough to cover (that is,
within 50 to 100 yards) as to be habitable for quail in winter.
A far smaller proportion furnishes the food and cover combin-
ations requisite to a regularly habitable covert. While ordinary
small farm crop rotation, fall plowing, or heavy pasturing of
312
occasionally cultivated fields may not be followed by extreme
fluctuations in carrying capacity for quail, profound environ-
mental changes involving large blocks of land may cause
fluctuations of great irregularity and violence, from one
extreme to the other. A given central Iowa farm may be well
stocked with quail one winter and barren of them the next,
according to fortuitous differences in food and cover combina-
tions; hence, it can readily be seen that determinations of
carrying capacity are likely to be most accurate when made
on lands divided into smaller fields.
WINTER MOBILITY AND BEHAVIOR OF BOB-WHITE
POPULATIONS
The bob-white is one of the few species for which the
practicality of censusing by direct enumeration has been
demonstrated. That direct enumeration may have its limita-
tions should be obvious to anyone of biological understanding;
counts may be excellent or worthless, just as any measurement
may be excellent or worthless, according to the skill of the in-
vestigator and the difficulties presented by the problem.
Direct enumeration of winter bob-white populations is
immeasurably facilitated by the relatively sedentary habits of
the species at this season, and it should be to advantage to
discuss usual and exceptional covey movements in some detail.
After the "fall shuffle" previously described, or the reori-
entation of coveys in prospective winter quarters, there is likely
to be little shifting on a considerable scale except in response
to necessity.
During periods of snow, it has been possible to determine
that the cruising radii for coveys living under favorable con-
ditions were short, and that the birds could usually be flushed
within a quarter mile of the same place at each visit. This
observed partiality of coveys for given winter territories has
been substantiated in the north by banding results [Errington
(18)].
Coveys show a tendency to develop a living routine, which,
if safe, they cling to indefinitely. Shooting, attacks by the much
feared Cooper's hawk [Errington (13)] or continued distur-
bances as by wood cutting may cause pronounced modifications.
in covey habits but seldom drive the quail altogether out of
their territories. The birds usually station themselves in
another part of their established range to avoid danger or
annoyance, assuming, of course, that other parts of their range
are habitable.
Even if undisturbed and well situated a covey may now and
then move considerable distances for no apparent reason. One
such covey was known to have travelled 1.2 miles in a straight
line in 1 day, to return shortly, and thereafter to make no
313
recognized departures from its regular territory during the
greater part of the winter.
Commonly, however, a covey does not move about greatly
unless it has to. Hunger is a powerful driving force and may
not only lengthen the cruising radius of an established covey
in its foraging for food (uninterrupted journeys of a half mile
are not unusual for moderately hungry coveys, though usually
the quail keep within their regular territories), but may be the
cause of chaotic and desperate winter shifting.
The reaction of a covey to a food shortage seems dependent
upon the onset and severity of the crisis. Sudden and complete
failure of the food supply may drive a covey out of its territory
altogether. If the food failure is gradual, the birds may merely
spend more time foraging or may starve slowly and passively.
Whether the crisis comes on suddenly or gradually, one cannot
predict with certainty what the birds will do; they may or may
not leave.
Much of the winter movement which takes place on a large
scale may be attributed to wandering coveys that have no
really suitable place to stay and never have had since fall. These
wanderers represent to a material extent the doomed over-pop-
ulation of the year or those evicted by wholesale destruction of
habitats, as by burning, plowing, or "cleaning up" of brushy
roadsides or fence rows. Some territories are consistently
deserted before the winter is over, although the coveys in a
shifting state may prove to be worse off than they were even
in inferior but established range.
Except for those coveys moving from distinctly uninhabit-
able or lethal environments and the comparatively minor
proportion that safely station themselves in the vicinity of farm
yards to feed with the chickens or stock or about the granaries
(ordinarily a wise move for an adaptable or an exceedingly
desperate covey), widespread winter shifting is not likely to
bring any pronounced change for the better for a restless and
ill-situated population. Nearly everywhere the first rate
environment is already occupied to capacity, and for shifting
coveys the poorer grades are not likely to be much of an im-
provement over those left behind.
The proximity of bob-white coveys in an area seemingly
influences movement to a considerable degree, for specific
intolerance becomes evident as densities rise past a certain
level. The bob-white is gregarious enough to combine in
coveys, but ordinarily displays an antipathy toward heavy con-
centrations.
4. Sometimes the intolerance is inter-specific, as indicated by reactions of bob-
white coveys toward concentrations of ring-necked pheasants [Errington (19), (20)].
314
The fall strife between whole coveys now and then recorded
[for example, see Errington (24)] is probably a manifestation
of territorial intolerance. This is distinct from the breeding
season combats, well described by Stoddard (70). It is possible,
however, that most adjustments may be made without a great
deal of violence, despite the frequent hostility and combative-
ness to be witnessed throughout the winter. The bulk of the
evidence seems to indicate a tendency on the part of winter
coveys-even when pressed by extremity-simply to avoid
coverts that are well populated already.
Rarely have we counted more than 35 bob-whites in inti-
mate covey combination, though we have recorded temporary
associations somewhat in excess of this number, largely as a
consequence of emergencies. Whether avoidance of over-
crowding may be due to compulsion, to instinctive reaction, or
to experience (by which much of their behavior is governed) is
problematical. Stoddard (70 p. 64) suggests that attacks upon
strange birds introduced into bob-white wintering pens on
game farms "may lie in an instinctive desire to prevent addi-
tional birds from sharing an already over-crowded range."
In areas sparsely populated with quail, the birds seem to
exhibit a greater freedom of movement than do birds of more
populous surroundings. Movement may be necessitated by the
poor quality of the environment, but this is not wholly explan-
atory. There may be only a single covey in a large tract of land
as a whole uninhabitable for quail, yet the environment may
be locally excellent where those few birds live.
COMPOSITION OF THE BOB-WHITE COVEY
Stoddard (70 p. 169) defines a quail covey as "an aggrega-
tion of individuals of convenient number (10 to 30), regularly
inhabiting an area that provides such essentials as food supply
and a sheltering vegetation of favored kinds and in proper
abundance."
It is but a unit of convenience and of no fixed number or
composition. It may begin as a family group, but it is not likely
to remain as one during the winter, except under conditions in
which bob-white populations are so very sparse that additional
birds do not occur for miles. Greater or less interchange
between neighboring broods and coveys takes place, and as an
end result the winter covey may contain young birds of differ-
ent ages, plus miscellaneous adults, including not only parent
birds but also those that were unsuccessful in mating.
Stoddard's banding studies (70 pp. 169-182) constitute the
most voluminous source of data on this subject. Banding
records from Wisconsin [Errington (18)] are in essential
agreement with Stoddard's findings, but they indicate, as might
be expected, a lessened interchange of birds between winter
315
coveys. Wisconsin field studies, moreover, have shown, with
some exceptions, a greater constancy of covey composition.
Coveys in lightly to moderately populated areas of southern
Wisconsin are usually made up of the same individual birds for
weeks at a time.
The degree to which coveys preserve their identity is par-
tially dependent upon the nearness of other coveys with which
they may come in frequent contact. Less interchange is
likely to take place between coveys having only occasionally
overlapping cruising radii than between coveys living in closer
proximity. Stoddard and Errington both found this to be the
case.
Even under crowded conditions Errington (20) found some
coveys maintaining their identity in a remarkable manner: "As
an extreme, one covey of 4 was noted to keep strictly to itself
for some weeks, although it shared a territory with another
covey of 12. Commonly, small groups like this are absorbed by
larger units [Stoddard points this out very plainly, also].
Coveys of 6 to 8 are often found separate, however, where they
have plenty of opportunity to combine with other birds. One
would hardly expect these small coveys of distinctive sizes and
exhibiting distinctive behavior for protracted periods to be
composed of any save the same birds.
"It is a common occurrence, too, for small coveys to unite
with larger ones (such as one of 8 with another of 12 to form
a covey of 20). A recently combined covey is usually weakest
at its point of junction; the above would probably split into its
component parts (8+12), but not invariably (it may split as
7+13 and 9+11). Sometimes more than two coveys combine,
as in a fairly well isolated area at Prairie du Sac, Wis., in 1930-
31 where coveys of 9, 15, and 245 coalesced-2 birds lost, 1
gained [influx from outside]-to give at different times [counts
of] 30+17, 29+18, 28+19, 27+20; the converse may likewise
be illustrated by another Prairie du Sac area in which coveys
of 15, 16, and 315 split up and recombined as 10+12+16+24 and
in other ways. In these latter instances the exact composition
of the coveys could not have been determined except by band-
ing or marking, but the total of associated covey groups was
remote enough from those of bordering areas to reduce the
chance of interchange with outside birds.
"Splitting and recombining is almost inevitable when a
remnant of a decimated covey joins with one already topheavy
numerically. If, let us say, a little group of 5 joins a covey of
30, thereby raising the total to 35, which the quail seem to sense
as a dangerous or unwieldy concentration, the 35 may split into
more desirable units of 15+20, 16+19, etc . . .
""
5. The occurrence of 24 and 31, or exactly half of the respective populations
resident at the time, in single coveys is looked upon as a fortuitous coincidence. These
examples were selected from many because they were especially clear-cut and were
founded upon reliable data,

316
Some sort of splitting of large coveys is virtually a necessity
for resting and roosting, as at these times the birds sit tail to
tail in compact bunches. Resting or roosting birds as a rule
bunch up in groups located within a few feet of each other, but
component groups of the same general covey are often found
many yards apart or may go off in different directions. Such
separations, frequently noted, are of brief duration, but some-
times the component groups do not rejoin at all; they may
even join other coveys or similarly split component groups off
other coveys.
With the approach of the mating season in the spring, rest-
lessness within the covey units becomes conspicuous. As early
as February, males and females leave the main body of the
covey in twos and fours for short periods. By March, there is
more and more pairing off, but cold or stormy weather brings
the birds back into covey formation. Birds may still be loosely
paired and attached to the old coveys, but the flocking habit
gradually weakens. April generally witnesses the final disin-
tegration of the covey unit for the breeding season.
To summarize: Prior to the dispersal of birds in connection
with breeding activities, the composition and behavior of the
bob-white covey under North-central States conditions have
shown sufficient regularity and irregularity both to aid and to
handicap census studies.
Interchange of birds with neighboring coveys; splitting and
recombinations of coveys and covey fragments; daily move-
ments of coveys on account of living routine or random impulse
or disturbance; population shifting in search of territories,
food, or to escape harassing predators (man included), or
for no discernible reason; all these represent departures from
static conditions.
It is our opinion, however, that much as winter bob-whites
may move within and without definite covey ranges, they rarely
move into territory strange to all of the members of the covey.
The radius of familiarity of an individual is doubtless of
greater significance in delimiting movement than the boun-
daries of its ordinary territory. In other words, while an
insecure covey may show no partiality for any particular
territory and may wander far and wide, the probability is that
its wandering will be rather definitely confined to a specific
area, though that area may be several square miles in size.
With all the exceptions noted, the winter bob-white at low
to moderate densities is still a comparatively sedentary species.
It usually does not move nearly as much or as erratically as its
occasionally demonstrated mobility and its physical powers
would permit. By and large, it is a species especially amenable
to direct enumeration census studies by competent observers
under favorable conditions.

317
DIRECT ENUMERATION CENSUS TECHNIQUES FOR
BOB-WHITE
A brief discussion of winter census techniques has been
published in connection with the Wisconsin studies [Errington
(20)] but, in view of subsequent experience and the constantly
growing demand for information, we believe that it would be
advantageous to revise and present our material on this subject
in greater detail.
Some preliminary remarks may be in order. In the first
place, reliability of census figures-assuming that the observer
is competent-varies roughly with the presence or absence of
tracking snows, with the time spent on a given area, with the
size of the area under observation (up to manageable limits),
and inversely with the density and the insecurity of the popula-
tion.
All snows are not tracking snows; those of icy consistency
glazed over by sleet or by sun do not register the tracks of a
bird weighing less than a half pound. A drifting snow or one
bespattered by falling icicles and water drops also is not the
best for tracking purposes.
Thaws may soften much crusted and hard drifted snow,
however, so that it furnishes an excellent register for tracks,
especially of birds active during the warm part of the day. Im-
prints made in wet snow are often preserved by night freezing
until they have been melted out the next day, and even then
their traces may be clearly distinguishable. Thaws may not
aid, however, in the censusing of coveys that restrict their
activity more or less to the morning when snow surfaces may be
impervious to their tracks because of freezing of the wet snow
during the night.
The amount of time necessary to keep an area under ade-
quate observation depends upon the difficulty experienced in
obtaining censuses and upon what may be happening. If the
studies are intended to be really intensive, covey groups should
be visited every week or two for the duration of the winter-
provided the birds are getting along fairly well and that the
counts at each visit are reasonably satisfactory. If the investi-
gator is having trouble in finding the birds or their tracks, or if
current developments (heavy predation, poaching, population
shifting, starvation emergencies, etc.) necessitate closer obser-
vation, it may be well to make visits every day or two, at least
during such periods of confusion and crisis.
Sometimes it is necessary virtually to comb an area over and
over again to extract the significant details of the ecological
drama which may be taking place. We may say parenthetically
that an observer learns with experience to cover an area with
a maximum of thoroughness and a minimum of disturbance of

318
the birds themselves and a minimum of interference with the
natural order of events.
In general, areas or samples chosen for observation should
be large enough to reduce the likelihood of complications
through interchange of birds with uncensused coveys outside,
yet small enough to be within the power of the observer to
handle. We have found that a tract of land 1 square mile in
area is about as small as may be profitably kept under observa-
tion, and this unit is often too small for reliable study when
much population movement takes place. As an upper size limit,
we believe that 5 square miles is enough to try to take care of in
one block.
Large rivers, lakes, solid tracts of forest or woodland, wide.
expanses of cleanly cultivated land, suburbs and towns, or
other physical features may provide virtual barriers to winter
bob-white movements and may be of great aid in census work if
they bound one or more sides of an observational area. Fre-
quently, actual studies demonstrate that many areas are so
effectually bounded by environment inhospitable to quail that
practically all winter influx and egress is restricted to a few
places that may be watched. For example, habitable winter
quail environment in much of central Iowa may be limited to
interrupted stretches of brush-bordered creeks, and may thus
serve somewhat as islands in the partial isolation of local
populations.
In general, the higher the bob-white densities in a given
area the more difficult it is to keep track of interchange.
between coveys and the increasing amount of splitting and
recombining. We have, for this reason, found ourselves quite
unable to census with real accuracy populations in excess of a
bird per 4 acres.
At a level of a bird per 4 acres, while local concentrations of
50 to 60 birds in constantly mixing coveys may frequently be
found on a 40-acre tract, these concentrations are likely to be
separated from other covey groups by unoccupied stretches of
perhaps a half mile or so. Under favorable conditions or by dint
of persistent and well directed effort, it is usually possible at
some time or other to secure nearly simultaneous check-ups on
the constituent coveys of such semi-isolated though densely
localized population groups.
At higher densities, there is less likelihood of finding semi-
isolated groups small enough to be censused in the necessarily
short time to prevent results being influenced by covey inter-
change and mixing. If a group of coveys is especially subject
to mixing, an investigator should strive to complete his
censuses within a space of 2 or 3 hours or at the most on 1 day's
tracking snow. Where one strong quail environment grades off
into another in continuous succession, there is slight chance of

319
being able to obtain accurate counts on all closely neighboring
coveys before mixing occurs.
Hence, well-handled censuses, which may be accurate to a
bird for low and medium densities, become more and more
inaccurate as densities rise, until for the higher quail levels of
a bird per 1 to 2 acres they may not at best be more than careful
approximations.
It goes without saying, moreover, that securely situated
populations are far more easily and reliably censused than
those that do a great deal of shifting in response to food short-
age, over-crowding, or eviction from former habitats. Indeed,
we have found the chaotic censuses of some populations quite
beyond our ability to straighten out, irrespective of the signifi-
cance of the ecological phenomena which this restlessness may
have reflected.
TECHNIQUE OF TRACK COUNTING
Track counts are of the greatest usefulness in bob-white
census work, especially if checked by flushing and counting the
birds at the end of fresh covey trails. Usually track counts are
obtained in snow, but under exceptional circumstances in sand
or mud.
As pointed out in the preceding section, the efficacy of
track counting as a census method is conditioned by the distri-
bution or the state of the snow. The difficulty of obtaining track
counts may be further increased by the absence of snow at
strategic places or by daily accumulation of tracks in an inde-
cipherable maze.
Erratic behavior of the quail themselves may add to the
difficulties. Well-fed coveys occasionally lie up without mov-
ing during the first day of a fresh snow, or do not venture forth
until late. In the event of an early morning snowfall, some
coveys may feed so soon after it becomes light that they may
not leave any tracks or only tracks so dimmed by the subse-
quent snow as to be uncountable.
Deep, fluffy snows cause the quail to fly instead of run from
one place to another, or to leave a trail that is a bewildering
series of short flights and shorter runs.
Snow of this consistency accentuates the tendencies of
coveys to run along in single file in packed trails. Bob-whites
also have a tendency to run in single file or in a massed
trail when gently alarmed, as by approaching people. For this
reason, an observer should be careful not to obliterate spread-
ing tracks with his feet until he has obtained a reliable count, as
the covey trail may grow worse the farther he follows it.
The best track counts can be made at points intermediate
between a covey's roosting or resting spot and its feeding
ground. At some point en route the covey trail usually widens
320
out enough to permit recognition and counting of the individual
trails (fig. 2). When the covey trail is partly massed and partly
open, it is sometimes possible to make accurate counts of a por-
tion of the covey at one point and of the remainder at another
(fig. 3). Where individual trails may be grouped in twos,
threes, fours, etc., for part of the distance, it may be advantage-
ous to block off groups for separate scrutiny and analysis.
It is imperative to watch the covey trail carefully, for a
lagging or an impatient bird may take wing and so leave no
tracks over part of the route. Repeated counts along the trail
(especially the trail of a large covey running in loose snow) are
necessary to reduce likelihood of error.

The directions of individual trails must be watched con-
stantly, as birds have a way of doubling back more or less in
the course of leisurely travel or when alarmed and undecided
(fig. 4). A single trail reversed but undetected may result in
an over-count of two birds. Commonly, satisfactory counts are
difficult to make in trails where there is much back-tracking
and massing (fig. 5). If the back-tracking is limited, and the
pattern is open, back trails and forward trails may simply be
cancelled out, one for one.
We have found chances best for making good track counts
on the margins of roadsides, on frozen creeks and sloughs, at
the edges of fields and open spaces where coveys may cross
smooth stretches of snow in spread-out formation. Irregulari-
ties in the trails where birds have either taken wing or have
alighted as strung-out coveys should be considered in census.
work, as well as trails of coveys incompletely assembled after
having been split or scattered. Counts on feeding grounds are
suitable if the coveys progress in some particular direction
without too much back-tracking or zig-zagging.
An investigator finds increasing familiarity with individual
covey habits of tremendous assistance in locating tracks or
birds without unprofitable search. Although very thorough
investigation should be made occasionally of all parts of an
observational area, quail-occupied or not, in practice, a hurried
survey of favorite coverts may be all that time allows, espec-
ially if the hour is late in the day or if an ephemeral tracking
snow is rapidly melting.
Certain strips of fencerow brush, certain hill slopes, certain
clumps of gooseberries, fallen trees, etc., may be preferred for
resting or sunning. There may be special bushes under which
a covey may like to scratch for fallen fruits. Other birds may
prefer habitually frequented sites for dusting or replenishing
grit. Others may regularly use such "highways" as ditches,
fences or ravines, or may approach feeding grounds from a par-
ticular direction, or may develop similar idiosyncracies of
which legitimate use may be made in census work.
321
λ
x
✓
↓
Y
*****
*****
.d.
*** & * t*t*t* ****
λ
******
Fig. 2. Trail of a covey of
9 quail, countable in places.
ተ
X
X
X
↓
x
<+
Κ
Κ
*
x x
+
+
↑入​↑
X
++
* **
دید
↑
xx
XX
****
Tipp
**
x
4
x
Fig. 3. Partly massed and partly open
trail of a covey of 13 quail.
322
K
K
K
K
*
xx
狱
​***
X
*.
V
*
X.
L
**
Fig. 4. Trail of a covey of 14 quail,
illustrating some back-tracking and ir-
regularity of movement.
+
+
↑
+
܀
+
+
X
X
++
Κ
L
fut
xxxx
*
XX DOK
xax+
*****
YX
X

X.X

Fig. 5. Difficult trail in which the
tracks of at least 13 birds can be made
out.
323
1
The danger of short-cuts in technique is that they may be
conducive to hasty inspections and carelessness. The judicious
use of short-cuts, however, may add to an investigator's
efficiency; in directing his course to include the most likely
coverts, he does not have to ignore those that may be less
frequented, or assume that they are not occupied.
FLUSH COUNTS
Counts of flying (or flushed) birds are relied upon chiefly
during winters when tracking snows are of rare or irregular
occurrence, or early in the season before tracking snows come.
Flush counts are also used during snow periods to verify track
counts.
In making flush counts, an investigator is beset by two
obvious difficulties: First locating coveys, and second obtain-
ing accurate counts of the birds.
Locating coveys without the aid of snow may be greatly
facilitated by the use of a trained dog [Wight (76)]. Dog-
users, however, may over-estimate the efficiency of their favor-
ite dogs and may depend too much upon them. Excellent as
may be a dog's nose and "quail sense," it by no means follows
that there are no more quail to be found on a given area simply
because the dog can not locate any more, vehement contentions
to the contrary notwithstanding.
A good dog if properly used may unquestionably be of
valuable help under snowless conditions, but the disadvantages
of using a dog as well as the advantages should be recognized.
A good dog cannot make up for lack of skill and diligence in
the human observer. Skill in both dog and man constitutes the
ideal combination, but of these two the skill in the man is more.
important. Indeed, it is our opinion that a truly skilled field
man may make a better all-around "bird dog" than the dog
itself, despite the fact that he does not have the dog's ability
to find birds by scent. A skilled field man can read the story
of quail droppings, dust baths, feathers, tracks and other "sign
when it is too old to interest a dog at all.
There are times in winter census work when a dog should
not be taken into the fields, particularly during tracking snows
when a dog may by his own tracks mess up covey trails at
strategic places so that counts cannot be made. The investi-
gator himself may have to watch where he steps amid the
individual trails, and dogs are seldom completely controllable.
On other occasions, dogs may cause quail to "freeze" when it
may be desired that they flush freely.
On the subject of flush counts we may quote again (20):
"A flush count is quite reliable for use with small coveys
(5 to 10) and with those of moderate size (up to 20) where the
quail fly well spread out and are not continually shifting places.

324
A covey leaving a patch of thick cover such as a mat of creeping
juniper in a steady succession of singles, twos, and threes can
often be readily counted. Where a large flock bursts into flight
as a compact mass, it is virtually impossible to obtain an
accurate count, although an investigator, through increasing
familiarity with coveys, learns to estimate size within a bird or
two by general appearance in the air.
"Flush counts are of scant utility if the birds have been
disturbed and scattered a short time previous. Premature
attempts to reflush for count a covey previously flushed and
marked down are also unprofitable. Immediate reflushes are
invaluable, however, in detecting weak individuals in the covey,
for underpar birds may have the strength for a vigorous first.
flight but little more.
"Censuses of an area were planned in such a way that
flushed coveys were encouraged to alight in territory already
covered, so as to obviate the chances of their being counted
twice or confused with other birds. In actuality, things do not
work out as smoothly as planned, but the quail, through the
proper approach of their favorite rendezvous, may often be
guided into flying about where desired."
It might be added that flush counts present certain other
pit-falls that need to be guarded against. Sometimes two or
three birds flush apart from the main body of a covey, and, if
these rise behind or far to the side of an observer, he may not
see them. Some members of a covey may have their flight
concealed by obstructions to vision, low visibility and so forth.
Incompletely assembled coveys and individual members dis-
posed to hide rather than to fly when approached are a source
of error.
No one should be too sure of the census figures secured
from a single visit, even when aided by snow. Repeated visits.
and critical evaluation of results are essential for accuracy.
Running counts may be discussed in the same category as
flush counts. They may or may not be reliable, according to
whether all of the birds pass directly in the observer's line of
vision and are noticed before some birds disappear from view.
Counts may be confused by birds running back and forth, by
two or three dashing past abreast, or by lagging individuals
becoming alarmed, to turn back or veer to the side unseen.
Roadsides, open spaces, hollows in ditches, erosion gullies, or
ravines offer opportunities for running counts. Birds en route
to or leaving feeding stations may frequently be counted with
comparative reliability and ease.
COUNTS WITH THE AID OF COVEY RESTS AND ROOSTS
Counts of the body impressions on roosts are much less
dependable than any of the census techniques thus far dis-
325
cussed. This method should be used sparingly and only under
the conditions best adapted to it, and where even an undepend-
able method is better than none. We have found it most useful in
the checking up of coveys of approximately known size when
track counts were impossible and the birds could not be located
or satisfactorily counted in flight.
When a covey flushes from a roost after having been partly
snowed over during the night, clear imprints of individual
breasts may sometimes be evident. Imprints of breasts may
sometimes be distinguished also when quail roost on frosty
nights in soft, thick grass. The great drawback to the method,
aside from the indistinctness of body outlines, lies in the
possibility of roosting covey groups rearranging themselves in
the night. Relative quantities of droppings corresponding to
imprints may give a clue as to whether or not rearrangement
has taken place.
We have been unable to use the quantity of droppings on a
roost as a positive index to the number of birds, as the quantity
of droppings is dependent both upon the diet of the birds and
the length of time that a covey has spent upon a particular
roost. Night flushes of coveys by mammals, interruptions in
feeding of individual covey members during the day, or food
crises on account of snow or ice storms, introduce too many
variables.
Daylight resting places, however, seem to offer a trifle more
promise to an investigator. The birds bunch up for even more
variable periods of time than they do at night, but the bunched
group tends to be less compact, and feces from a few individuals
may frequently be detected in distinct little piles, although the
majority of the droppings may be scattered over a space of 2
or 3 square feet.
If the evidence indicates that these little piles represent the
droppings accumulated from the first birds to station them-
selves in any definite position during the time that the covey
was resting, and if each of the distinctly separate piles contains
about the same number of droppings, then it may be possible to
calculate the approximate number of birds in the resting covey
by dividing the total number of droppings by the average
number per separate individual pile. For instance, if the total
number of fresh droppings is 67 and the counts for three dis-
tinctly individual piles give five, five and six or an average of
five, the total of 67 divided by five establishes the number of
birds in the covey in the vicinity of 13.
We have found, by checking calculations of this sort against
actual censuses of the coveys which had been on the rests, that
our likelihood of error ordinarily does not exceed 20 percent.
This percentage is far too high for work that demands precise
survival figures, but it is often very useful to determine, when
326
birds can neither be found, nor censused, whether a given
territory is occupied by many birds or few.
INTERPRETATION OF CENSUS DATA
Interpretation of bob-white winter census data may be com-
paratively simple or may be beset by the most formidable of
difficulties. The difficulties are usually in direct proportion to
the density of the quail population studied and the amount of
covey interchange and shifting which have taken place. Further
difficulties may be presented by lack of data at strategic times.
When the total quail population of an isolated piece of land
was only, let us say, a covey of nine birds at the beginning of
the winter, of which eight were known to have survived and
the other was known to have been killed by a horned owl, the
investigator may regard his data with a certain confidence, so
far as they go. But when the season's notes show a succession
of coveys appearing and coveys disappearing and census fluctu
ations for territories regularly occupied as well, the fragments
of evidence have to be fitted with care if a truthful picture of
what happened is to be reconstructed. Of course, if the data are
too chaotic, any refinement of deductions would be spurious,
and the most one could extract
from them would be broad and
evident generalizations.

Let us consider a fairly com-
plex example of raw but essen-
tially workable wintering data
from part of an observational
area near Prairie du Sac, Wis.,
season of 1931-'32.
B
Figure 6 depicts the rough
outline of a series of occupied
bob-white ranges, themselves
more or less contiguous but
separated by significant dis-
tance or by effective barriers
from occupied territories out-
side. The general covey head-
quarters are designated by let-
ters, and the locations of out-
side coveys by asterisks. The
asterisk-indicated coveys were
sometimes near, but their terri-
tories did not conspicuously
overlap those of the coveys to
be considered, nor was ex-
change of birds known to have
occurred within the period covered by the present data.
с
O
E
G
D
· H
Yo
SCALE IN MILES
Fig. 6. Outline of a series of contigu-
ous bob-white covey ranges near Prairie
du Sac, Wis., winter 1931-32. Letters
represent general covey headquarters in
this group of territories; asterisks, near-
est outside territories.
LL
12
327
For territory "A," counts of 14 were made on Dec. 12 and
Dec. 22. From Jan. 10 on, the birds were no longer to be found
I here.
|
For the territory adjacent to the east, "B," the count on
Dec. 18 was 18. On Jan. 10, coincident with the disappearance
of the covey of 14 ("A") on the west, the count was 32, a gain of
14. This certainly gives the basis for a good guess as to what
happened.
On Jan. 16, 32 birds were again counted, but as split up
coveys of 18 and 14. The inference is plain that the 32 birds had
separated into their original covey groups, although they were
now occupying the same range.
On Feb. 3, 14 were found and the whereabouts of the other
covey was known, but the latter couldn't be flushed. By Feb.
10, the arrangement was a little different: 15 and 17; Feb. 25,
the same. On March 12, the count was 15 and 15, which, as a
final figure could indicate the loss of two birds. The suspicion
of mortality, however, was partially dispelled by locating a
I covey of 17 on March 19; and on March 23, the full 32 were
present, but now arranged as 9 and 23.
Territories "A" and "B" furnish data almost ideally inter-
pretable, since the interchange was confined to only two coveys
in the first place, and since these coveys were closely adjacent
and observable with comparative ease. The situation also was
not complicated by much irregular movement or by mortality.
More complex are the data from territory "C," and in the
absence of supplementary data from territories outside, it
would be hopeless to try to do much with them.
On Nov. 1, the count was 19 for "C"; on Nov. 18, the birds
couldn't be found; on Dec. 9, there were 14. So far, the data are
in a veritable muddle and would likely remain so were it not
that territory "H," adjacent to the southeast, was known to
have gained about five birds in the interim. Had territory "H"
not been under observation at the time, we could not have made
an intelligent guess as to whether the missing birds had been
killed, had moved out, or whether the territory had not been
abandoned by the original covey, later to be occupied by an en-
tirely different one. The story is not yet completely clear, but
the evidence pieces together rather nicely.
Subsequent counts showed no change until Jan. 5, when the
covey gained one bird, thereby bringing the number up to 15.
The gain was soon lost, for by Jan. 9, the covey was down to
13; the newcomer had probably joined for temporary conven-
ience after some scattering of its own covey, later to go back
where it belonged.
On Jan. 28, covey "C" was down to 11; Feb. 6, the same;
10 on Feb. 17; and 9 from Feb. 27 to March 16. The shrinkage
328
from 14 to 9 probably in the main represents mortality, though
our field data give us little answer as to specific causes. Gradual
decline is much more apt to indicate mortality than sudden
disappearance of a number of birds at a time.
Next, we have data virtually impossible to interpret cor-
rectly without thorough familiarity with the situation as a
whole.
In territory "D" about 22 birds were counted on Oct. 30,
never to be found there again.
The same number were counted Dec. 8 in territory "E,” a
territory previously unoccupied. The birds were never found
here again either.
Territory "F," likewise previously unoccupied and soon
deserted, had 26 birds on Dec. 18.
Finally, a large covey appeared in the previously vacant
territory, "G." The first count, on Jan. 10, was 23. The covey
elected to stay here, but lost steadily from the beginning. Fol-
lowing counts were: 22, on Jan. 16; 16, Feb. 3; 13, Feb. 10; 8,
Feb. 25; 7, March 3; 4, March 12; and but 2, March 23.
It was apparent, from scrutiny of the current census data
from surrounding territories and from prospective though
unoccupied quail habitats, that the territories "D," "E" and
"F" simply represented stopping points in the wandering of
the covey which eventually stationed itself at "G," at a distance
of nearly a mile and a half from the place where first noted.
The soundness of evidence as circumstantial as this is depen-
dent upon the quality of the data pertaining not only to that
part of the population which is shifting, but also to that part
which is comparatively sedentary and established.
The losses shown by territory "G" represent mortality from
predation, terrific and conspicuous. The gradual, constant
shrinkage alone would indicate as much, even had the remains.
of birds not been scattered all over the territory and had not the
winter's killing been traced almost completely and exclusively
to great horned owls.
Later on in this bulletin, the interpretation of data will be
carried on much farther, and the recorded lethal history of ter-
ritory "G" will be presented for analysis, season by season.
TECHNIQUE OF TRACING MORTALITY
It has been found advantageous to locate the coveys of a
prospective observational area rather early in the fall. Even
before reliable censuses can be taken, the whereabouts of
coveys may often be ascertained by listening for quail calls and
by the reading of "sign" from roosting and resting spots,
scattered droppings on feeding grounds, dust baths and
feathers.
It is plain that the more nearly absolute a census, the greater
329
will be its value in determining whether coveys are suffering
losses. The disappearance of a bird from a suitably isolated
covey or group of coveys (with no subsequent reappearance or
no corresponding gain by surrounding coveys) may be accepted
as a strong indication of mortality, but the investigator should
not be so easily satisfied. His next step should be to search the
environs for remains of the missing bird and for explanatory
"sign."
In many instances (perhaps 50 percent, under favorable
conditions) in which birds were known to drop from observa-
tional coveys, we have been able to piece together fairly good
evidence as to what happened. Our fortunes, however, in
tracing the causes of mortality have vacillated from one ex-
treme to the other. Practically all birds missing from some
coveys have been accounted for, while in others the majority
of disappearances could not be solved. In general, the com-
pleteness of the observational data which an experienced
observer obtains from an area varies with the time spent.
It is also possible to trace some types of mortality with far
less difficulty than others, but the activities of scavengers are
a major source of confusion.
Large and medium sized slow hawks, such as marsh hawks,
red-tails and rough-legs, and such enterprising mammalian
predators as foxes, house cats and minks are constantly feeding
on carcasses, including those of quail, which they may have
killed but which they more likely found dead. Prey in posses-
sion of or eaten by Cooper's hawks or great horned owls com-
monly represent kills made by those predators. Evidence of
crows, skunks, oppossums, dogs and meat-hungry rodents
about remains of adult quail almost without exception denote
scavenging.
Feather "sign," in the case of the death of a bird no larger
than bob-white, does not long remain conspicuous. It may be
completely hidden by a light fall of snow or may be made very
difficult of detection by wetting, as by rain or melting snow and
ice. Wind action, falling and drifting leaves, and mice (which
have been known to carry off quail feathers for nest lining) may
destroy the evidence in a short time. Unless the same ground
is covered every 2 or 3 weeks, feather remains which might
definitely account for missing birds may easily be overlooked.
Relative to the pitfalls attending the interpretation of preda-
tor kills, a few paragraphs may be directly quoted [Errington
(14)]:
"Of fundamental importance to those carrying on a life
history study of a given species is the ability to read sign when
a kill of that species is found. This ability is acquired slowly
and never can begin to approach perfection, if for no reason
other than the imperfection of the sign itself. Always must

330
1
the investigator watch himself, lest he find out things that
aren't true.
"Perhaps it would be in order to review a specific incident.
On December 24, 1930, the remains of a quail were seen in a
railroad ditch south of Madison, Wisconsin. The sign was
two days old. An empty shot-gun shell lay on the grade sixty
feet from the quail and there were two wads on the snow be-
tween quail and shell. No shot pattern could be located. Cat
tracks were noted about the quail remains, and it was obvious
that the cat had partaken thereof. A search in the snow brought
up a portion of a quail skull, with marks of two canine teeth
where a piece had been bitten off. The tooth marks were too
close together for cat. To the side of the track-beaten space
were rather indistinct prints of mink. The canines of a mink
skull checked with the marks on the quail skull. But along with
the quail skull a wing had been dug out of the snow-a wing
showing the typical clean plucking of an accipitrine hawk. Since
a wintering Cooper hawk had been flushed on December 20th,
from a warm quail killed out of a neighboring covey, the evi-
dence was now about as clear as circumstantial evidence ever
is.
"This kill, fairly fresh and rendered conspicuous by snow, is
illustrative of how in one way or another the fleeting records.
of the wild fade into illegibility. Suppose that the wing had
disappeared, or both wing and skull? Suppose that the kill had
not been seen until days later, and the site had been inspected
in the meantime by
other flesh-eaters not averse
to scavenging when that is easier than hunting? Suppose that
the kill had taken place in summer, a week previous to dis-
covery, and rains, putrefaction, maggots, ants . . . . . had had
their part in the obliteration of the story?"
The prompt discovery of a dead bird, before scavengers or
weather have blotted out the "sign," is therefore a substantial
step toward diagnosis of the cause of mortality. Profitable
places to look over upon the disappearance of birds are recent
roost sites, fencerows, the borders of brushy cover, the ground
beneath large or vine-entangled trees and any likely retreats of
suspected predatory species.
•
Starving bob-whites found dead in cold weather leave a
story that can be read, as well as do fresh predator kills. If a
predator kill is not distinctive enough, it may conceivably be
checked up by means other than by "sign reading," especially
where remains may be retrieved later, as from raptor nests or
pellets. Familiarity with the food habits of the quail coveys in
horned owl hunting ranges has been of aid in tracing unbanded
victims to their coveys, on the basis of undigested quail food
contained in the pellets [Errington (14)].
The normal shedding of quail feathers on roosts or rests

331
should not be mistaken for evidence of mortality. Flight
feathers and small feathers attached to particles of skin, on the
other hand, are much more significant. Indeed, one may some-
times find, on the primaries of plucked prey, outlines of raptor
beaks sufficiently distinct and characteristic for identification.
In the majority of instances, unfortunately, there do not seem
to be imprints which one would be justified in accepting as
wholly diagnostic. Bill marks of the larger raptors we have
found to be most recognizable.
If the carcass is that of a freshly killed quail, one may
frequently identify the work of a specific predator or predator
group, but one should bear in mind that the technique of a
predator species in handling prey is by no means uniform.
Foxes and house cats bite off and leave the wings of their
victims. Wings roughly plucked and heads gone may indicate
horned owls or large hawks; if the prey is eaten by hawks, the
stronger bones of breast and shoulder girdle are likely to be
left, whereas horned owls with their powerful beaks shear
through bones and flesh alike, and often leave nothing after
the first meal except hindquarters. Marsh hawks and Cooper's
hawks pluck the primaries and leave the head sometimes intact,
sometimes partly eaten. These two have a common habit of
eating the flesh from the upper breast first; but much cleaner
plucking of the wings is an accipitrine trait-although a small
accipiter may not attempt any wing plucking. Stoddard has
found the Cooper's hawk trait of swallowing the legs of a
quail victim after decapitation to be perhaps more general than
we have observed in the North. Viscera may be relished or
discarded, according to the taste of the individual predator.
The differentiation between carrion and killed prey is ex-
tremely important in field studies and in the correct interpreta-
tion of data from predator stomachs, etc. It may, moreover,
be extremely difficult if not actually impossible to do, under
many circumstances. Generally, bloodiness of tooth or talon
marks indicates a kill. The presence or absence of connective
tissue about the base of scattered primaries may be of some
assistance in indicating whether they were pulled from a warm
kill or pecked loose from a cold carcass. Those portions which
have been eaten may provide the best lead in evaluating the
evidence, as some parts of a fair sized carcass are less preferred
or are seldom eaten except when cold. For example, if a hawk
stomach contains nothing except the tail feathers, synsacrum,
and bony fragments ordinarily not eaten, one may reasonably
judge that there wasn't much left of the carcass when the hawk
started to feed. Of course, unanswerable questions are always
arising as to whether material eaten as fresh carrion was found
dead in the first place or represents killed prey to which a later
return was made.
332
Other leads may be helpful, such as the site of killing or
picking or eating, probabilities based upon intimate knowledge
of local predatory species, habitual and adaptive behavior of
the quail coveys preyed upon, and sundry minor clues; but, in
the absence of anything indubitably characteristic, one should
not try to come at once to definite conclusions. One should
never be hasty in the interpretation of evidence, for it is very
easy to record opinion as fact. Carefully written descriptive
notes, however, have a permanent value which is more than
likely to be enhanced by time and by maturity of experience.
MORTALITY FROM POACHING
While feather evidence is usually to be found when winter-
ing quail suffer mortality—though the "sign" may be so poor
that it may only confirm the loss of a bird-a notable exception
must be taken into account where human poachers have been
active. Often there is little to point to shooting except the
vanishing of birds, or perhaps a crippled or killed bird over-
looked by the hunters.
Occasionally, one finds where a quail has been shot on the
ground or where a handful of feathers has been cut off or torn
out by a shot charge. Two or three or a half dozen birds may
suddenly be gone from a well established covey; wild-flushing
remnants of coveys formerly tame may be encountered; there
may be gossip about the neighborhood; but the work of the
poaching hunter is exceedingly hard to trace down with any
definiteness.
Even more difficult to trace down is the work of quail
trappers, unless one finds the actual trap or its former site.
Quail are at times easily attracted to certain places by feed and
are readily caught in wire cage traps of various designs. Whole
coveys or the greater part of whole coveys may now and then be
caught in one trap at the same time.
It is apparent that quail trapping on an area might invali-
date data from many covey territories. On the whole, however,
we have no reason to believe that undetected shooting or trap-
ping has significantly reduced winter populations on our best
observational areas. Despite the reduction or total disappear-
ance of certain coveys under suspicious circumstances, we have
found that many covey disappearances without trace may sim-
ply signify movements and that the birds may be relocated if
enough searching is done.
The occasional propensity of acorn-feeding coveys to range
in solid blocks of wooded hills, or of coveys to station them-
selves near the centers of large cornfields for varying periods of
time, may be a cause of confusion to an investigator, especially
subsequent to the disappearance of those coveys from coverts
previously occupied with regularity. Release of an extensive
M
333
food supply from snow or ice by a mid-winter thaw may induce
rather widespread covey movements, notably after a population
had been confined to definitely restricted habitats because of
prolonged severe weather.
PART II. SURVIVAL DATA
EVALUATION OF WINTERING DATA
During the first three winters of the Wisconsin quail inves-
tigation, Errington, aided by Albert J. Gastrow of Prairie du
Sac, Wis., located for study approximately 2,650 birds in 155
coveys. Of these birds, about 1,600 were kept under regular
observation, roughly: 400 from October, 1929 to March, 1930;
500 from December, 1930 to March 1931; 700 from December,
1931 to March, 1932. Particular attention was paid to the in-
fluence of food, cover and predation upon winter mortality; and
miscellaneous factors bearing upon the problem were given the
consideration warranted by their apparent importance.
In the first winter of the Iowa cooperative studies, 1932-33,
Errington and Hamerstrom and cooperators in Wisconsin and
Iowa, located 84 coveys totalling about 1,250 birds, of which
nearly 900 were kept under regular observation from Novem-
ber to March.
The field studies for the winter of 1933-34 were conducted
on an extensive scale and were checked by a comparatively
small amount of intensive work. Errington, Hamerstrom and
Deputy Game Warden C. H. Updegraff (Iowa Fish and Game
Commission) obtained data of some sort on 453 coveys totalling
about 6,450 birds. Only about 580 wintering quail were
regularly observed (most of these by Gastrow), according to
standards acceptable for really reliable data, and those from
October to April.
During the last season, 1934-35, renewed emphasis was
placed upon intensive local studies, and about 870 birds were
kept under regular observation out of the total of about 1,300
in 110 coveys upon which some data were secured.
Altogether, then, from 6 years study we have more or less
data on about 11,650 quail beginning the winter in about 800
coveys, of which the data on nearly 4,000 birds may be said to
be superior. Of the 11,650 total, about 7,750 were Iowa birds.
studied on 29 areas; the balance were birds on 15 areas in Wis-
consin and 2 in Minnesota.
For data, which we evaluate as superior, we believe that
the possible error in census figures rarely exceeds 5 percent and
in a majority of instances is decidedly lower than that, ranging
down to complete accuracy. Exactness in census figures, how-
334
ever, should not be confused with exactness in mortality deter-
minations. It is one thing to discover that birds are missing
from a covey or territory and another thing to establish clearly
the cause of their disappearance.
The winter survival data from specific covey territories or
groups of adjoining territories may for analytical convenience
be separated according to their reliability and to the degree to
which they are affected by complicating variables. All numer-
ically reliable data obtained from identical territories under
observation for two winters or more are presented. Data are
placed in different reliability brackets on the basis of the
technical criteria by which they may be judged, not on the
basis of anything they may seem to prove or disprove.
The predominance of Wisconsin over Iowa data in the
tabulations is marked, although we have had greater numbers
of birds under observation in Iowa than in Wisconsin. It simply
happens that bob-whites have been far more accurately cen-1
sused under Wisconsin conditions and that many of the Wis-
consin territories have been under regular observation for long-
er periods of time. Wisconsin bob-white populations and en-
vironments alike have on the whole shown more relative stabil-
ity during the years of these researches, and hence have been
more productive of scientifically acceptable data on maximum
winter survival.
SURVIVAL DATA-FIRST CLASS
(Data from more or less regularly occupied territories bounded on
all sides either by territories similarly under observation or by wide
quail-vacant spaces or physiographic features serving as barriers to
winter movement; data relatively uncomplicated by starvation emer-
gencies or by heavy losses occasioned by factors other than predation or
egress.)
·
TABLE 1. TERRITORY NO. 1
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count
17 on Dec. 4
23 on Dec. 21
11 on Oct. 24
21 on Dec. 7
27 on Oct. 22
11 on Nov. 12
PRAIRIE DU SAC, WIS.
G

Final count
17 on Feb. 15
17 ? on Mar. 15
7 on Mar. 2
17 on Mar. 25
18 on Mar. 29
16 on Mar. 25
Cause of difference
No loss
Predation; some shooting
Probable predation,
but atypical
Predation; auto traffic
Mainly egress
Influx; much interchange
Of the final counts for territory number 1 (table 1) on
consecutive years (17-17 (?) -7-17-18-16), the substantial loss
from predation of 4 out of 11 for 1931-32 when the territory
was only partly occupied represents the probable mortality of
unusually immature birds. The original covey on Oct. 24 was
made up of an adult cock and 10 very backward young in no
way equal in winter survival potentiality to adult birds.
335
TABLE 2.
Season
1929-30
1930-31
1931-32
1932-33
TERRITORY NO. 2
M
First count
37 on Dec. 21
38 on Dec. 20
33 on Jan. 4
33 on Feb. 14
Season
1929-30
1930-31
1931-32
1932-33
LAKE WINGRA, MADISON, WIS.
Cause of difference

First count
10 on Oct. 25
22 on Jan. 6
16 on Jan. 9
Final count
23 on Mar. 28
32 on Mar. 29
29 on Mar. 11
33 on Mar. 29
All but one or two of the birds of territory number 2 (table
2) lost during the season of 1929-30 were lost because of late
winter starvation. Had it not been for this emergency, the
winter survival would have been in the vicinity of 35. In 1931-
32, a cold snap was attended by the disappearance of two birds,
possibly in poor condition. In 1932-33, while the period of
observation showed no loss, evidences of previous pressure of
great horned owls indicated that the population had been
reduced thereby to the 33 birds, which seems to represent a
level of comparative security from winter predation. The
majority of the 1932-33 observations, both at Lake Wingra and
University Hill Farm, were made by H. G. Anderson of Madi-
son, Wis.
TABLE 3. TERRITORY NO. 3 UNIVERSITY HILL FARM,
MADISON, WIS.
Mainly starvation
Predation
Predation and cold
No loss during observa-
tional period
Final count
0 on Jan. 26
19 on Mar. 17
16 on Mar. 19
Covey evicted by agricultural practices.
Cause of difference
Egress and freezing
Egress
No loss
-

During the winter of 1929-30, three birds of territory num-
ber 3 (table 3) simply shifted to an adjacent territory, but the
remaining 7 were apparently lost through what could best be
classed as a freak accident-chilling and freezing in good flesh
after their plumage had been saturated in sub-zero weather
by steam from a manure pile upon which they had roosted. A
temporary influx of 13 from territory number 37 had occurred
by March 23.
The eviction of the 1932-33 birds was due to the plowing
under or removal, in connection with farm routine, of pract-
ically the entire food supply available in the territory.
The carrying capacity for quail of number 3 and adjacent
territories was apparently lowered in 1930-31 and 1931-32 by a
rise in the pheasant population. A mixed stand of 47 quail and
about 30 pheasants was noted in 1930-31, and a stand of 26
quail and about 50 pheasants in 1931-32, totalling in the vicinity
of 77 and 76 gallinaceous birds, respectively, for the two
seasons on the 200-acre observational tract as a whole [Erring-
ton (26)].
336
1
TABLE 4.
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
Season
1929-30
1930-31
1931-32
1932-33
1933-34
TERRITORY NO. 4 PRAIRIE DU SAC, WIS.
First count
15 on Jan. 4
20 on Dec. 22
19 on Nov. 10
18 on Dec. 9
24 on Nov. 21
47 on Dec. 5
1934-35
M

Territory number 4 (table 4) was adjacent to territories
number 17, number 18 and number 19; and, taken for the four
territories collectively, the survival figures show a much
greater uniformity than for any territory individually, as will
be demonstrated later (table 22).
First count
31 on Dec. 1
48 on Dec. 21
75 on Nov. 25
125 on Dec. 12
151, mid Nov.
92 on Dec. 1
Final count
14 on Feb. 16
20 on Mar. 30
15 on Mar. 23
15 on Mar. 22
17 on Mar. 31
23 on Mar. 18
TABLE 5. TERRITORY NO. 5 — PRAIRIE DU SAC, WIS.
Final count
25 on Feb. 15
47 on Mar. 14
61 on Mar. 20
111 on Mar. 28
105, late Mar.
50, late Mar.
Cause of difference
Probably predation
No loss but see text
Probably predation
Egress and predation
Probably predation
Largely egress

Cause of difference
Largely egress
Predation
Starvation and predation
Principally predation
Principally predation
Mainly egress and
starvation
Territory number 5 (table 5) is in actuality a combination
of closely adjacent covey territories so overlapped and so
promiscuously covered by the quail population that any
attempt at further sub-division would be hopeless. The com-
bination of territories in this instance may then be regarded
as an environmental unit, differing from a circumscribed indi-
vidual territory only in scale.
During the first two winters of the researches, the territory
was not filled up to anywhere near its capacity, since the bob-
white population had not completed its recovery from the
terrific starvation mortality which it was known to have
suffered during the winter of 1928-29. Nor had full recovery
evidently been completed by 1931-32, though for the Prairie du
Sac areas as a whole the population had at this time ascended
past carrying capacity [Errington (26)]. A minor amount of
starvation took place in 1931-32, probably enough to contribute
decidedly to the rather high proportion of birds lost for the
population level indicated.
CWA roadside debrushing activities of 1933-34 may have
lowered the carrying capacity of the combined territories for
that season. In 1934-35, for a population probably below carry-
ing capacity, the predation loss was rather immaterial, but the
loss from storm and egress was high.
The data from territory number 6 (table 6) lose a great
deal of their heterogeneous aspect when considered jointly with

337
TABLE 6.
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
TERRITORY NO. 6 - PRAIRIE DU SAC, WIS.
Final count
24 on Feb. 15
34 on Feb. 1
First count
26 on Dec. 1
31 on Dec. 22
20 on Dec. 1
33 on Nov. 26
33 on Nov. 13
14 on Nov. 10
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
18 on Mar. 17
29 on Mar. 21
25 on Mar. 22
0 by Dec. 17
the data from adjacent territories. For example, the low sur-
vival for 1931-32 is easily explained by the fact that the
occupancy of another territory (number 54) (table 58) brought
about a condition of over-crowding on a comparatively small
area of common range; the combined survival for territories
number 6 and number 54 (actually inclusive with number 6)
was 37 instead of the 18 for number 6 alone.
First count
37 on Dec. 3
62 on Dec. 21
If territory number 6 is considered as a larger unit, embrac-
ing all occupied quail land occurring as a semi-isolated block,
between which and neighboring territories a surprisingly small
amount of winter interchange has been detected, we may recast
the data in a more intelligible way: (table 7).
60 by Dec.
65 on Dec. 9
106 on Nov. 21
72 on Dec. 1
Cause of difference
TABLE 7. TERRITORY NO. 6 AND ASSOCIATED TERRITORIES
(No. 12, No. 15, No. 16, and No. 54).
Predation
Influx: later lost
Influx of 4; loss of 6
atypical
Predation and traffic
Predation
Mainly egress to No. 53
Final count
24 on Feb. 16
62 on Feb. 1
46 on Mar. 15
53 on Mar. 21
66 on Mar. 22
50 on Mar. 18
Cause of difference
Egress; little predation
No loss; predation later
Miscellaneous mortality
Predation
Predation and egress
Predation; interchange
The population of territory number 6 and associated terri-
tories (table 7) for 1929-30 was distinctly below the carrying
capacity of the land, not having recovered from the starvation
losses of 1928-29. A small covey, finding an outside territory
partially occupied and attractive, had left by mid-winter. One
or two birds were killed by predators.
The 62 birds counted on Feb. 1, 1931, represent a too high
survival figure for the season, as a subsequent loss of at least 4
from predation was known to have taken place. For the season
of 1931-32, a mortality of at least 6 should be charged to
poaching and accident. The losses for 1932-33 and 1933-34 may
be attributable largely to predation, although 10 of the 40 birds
missing for 1933-34 apparently had moved out.
Leaving out the survival for the under-populated season of
1929-30, and making as correct allowances as we can for the
unrecorded late season predation of 1930-31 and the atypical
accident and shooting mortality of 1931-32, we would get more
nearly normal survival figures of 58-52-53-66-50, for the five
338
winters from 1930 to 1935. The 1933-34 population was plainly
top heavy and doubtless continued to suffer loss at a high rate
for some time after March 22.
Season
1932-33
1933-34
1934-35
Season
1932-33
1933-34
1934-35
TABLE 8. TERRITORY NO. 7-AMES, IOWA.

First count
57 on Dec. 17
42 on Dec. 13
53 on Nov. 27
Season
1932-33
1933-34
1934-35
Considerable debrushing of territory number 7 (table 8) had
occurred during the seasons of 1932-33 and 1933-34, but we
rather doubt now that the carrying capacity was affected to any
pronounced degree. In the season of 1934-35, however, fall
plowing of an entire large corn field, upon which the quail
population of the territory depended for food, resulted in a
wholesale though not simultaneous eviction. The largest covey
of 31 left first; by Jan. 15 but 4 remained. Except for this
eviction, the survival probably would have been in the vicinity
of 48, judging from the past records of wintering populations.
Final count
51 on Mar. 19
38 on Feb. 27
0 on Jan. 24
First count
23 on Dec. 17
23 on Jan. 13
22 on Nov. 22
Cause of difference
Predation
Predation
Eviction
TABLE 9. TERRITORY NO. 8- AMES, IOWA.
Final count
20 on Mar. 20
21 ? on Feb. 27
7 on Mar. 1

Cause of difference
Egress
Probably predation
Egress; some predation
We are not at all sure as to just what happened in territory
number 8 (table 9) during the season of 1934-35 [Errington
(32)]. The continued disappearance of one well situated resi-
dent covey after another in this general area without evidence
of mortality suggests trapping operations, but of this we have
no definite proof. Indeed, number 8 was the only territory in
one and a half square miles that succeeded in holding any quail
at all, on a tract that in 1932-33 had wintered 96 birds in 7
coveys.
TABLE 10. TERRITORY NO. 9 — FT. DES MOINES, IOWA.
First count
Final count
20 ? on Dec. 18
20 on Dec. 11
20 on Mar. 20
20 on Jan. 8
24 on Feb. 8
26 ? by late Dec.
Cause of difference
Loss of 1 from predation
Egress of 12 by Feb. 27
Predation
The territories surrounding number 9 (table 10), on an
observational area of about a square mile, were commonly not
occupied for the entire winter.
339
TABLE 11.
Season
1932-33
1933-34
1934-35
TERRITORY NO. 10 — Des Moines, IOWA, CITY WATER-
WORKS SUPPLY GROUNDS (WILD LIFE REFUGE).

Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count
59 on Dec. 16
59 on Dec. 8
14 on Nov. 23
The higher wintering densities of the first two seasons on
territory number 10 (table 11) were due almost entirely to the
excellence of the feeding program carried on by the City
Waterworks employees. During the past season, at our request,
the feeding program on the sample tract under observation was
experimentally delayed and restricted, with a resultant lower-
ing of the wintering bob-white population. The heavy influx
evident by March 1 may be attributed to the resumption of the
feeding operations and to food shortage on private lands adja-
cent to the area.
SURVIVAL DATA-SECOND CLASS
(Data differing from those of Class One in that they were secured
from territories not so likely to hold quail year after year; the territories
were, however, similarly bounded by barriers
or by territories
under contemporaneous observation, and the data were similarly un-
complicated by starvation or by atypical losses.)
Final count
55 on Feb. 8
54 on Feb. 27
33 on Mar. 1
TABLE 12. TERRITORY NO. 11 — PRAIRIE DU SAC, WIS.
First count
Final count
Cause of difference
Influx of 8 in early
January
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
22 on Jan. 4
Territory not occupied.
32 on Dec. 18 I 32 on Mar. 23
30 on Mar. 29
Territory number 11 (table 12) was a farmyard territory
offering a secure habitat as long as the birds could range
between a corncrib and a huge brush pile nearby. With the
burning of the brush pile, the territory lost its attractiveness, if
not much of its habitability. During 1934-35 a different part of
the territory was occupied by 10 of the birds; 9 used the old
range.
Cause of difference
Predation and egress
Predation and egress
Influx

I
No loss
Territory not occupied; birds evicted by the burning of a
strategically located brush pile.
14 on Nov. 14 1 19 on Mar. 22 I Influx; some egress
TABLE 13. TERRITORY NO. 12- PRAIRIE DU SAC, WIS.
First count
11 on Jan. 3
15 on Dec. 22
Territory not occupied
19 on Nov. 17
9 on Jan. 5
12 on Dec. 1
Getty

Final count
16 on Feb. 1
0 on Feb. 16
13 on Mar. 28
11 on Mar. 31
0 by Jan. 7
Cause of difference
Egress
Influx
Egress and predation
Influx
Mainly predation

340
Territory number 12 (table 13) is on the border line of
habitability and attractiveness and is situated between other
territories which are more desirable to wintering bob-whites,
though occasionally subject to over-crowding. As a conse-
quence, territory number 12 is the scene of endless shifting and
some mortality. Birds come and go, and sometimes, as in 1931-
32 when an excessive amount of fencerow debrushing took
place, the territory may not be occupied. In 1934-35, the
vulnerability of the resident covey may have been increased by
the temporary massing of a combined covey of 26 nearby
[Errington (32)]. The territory is one of the number 6 group,
and its populations are apparently influenced by densities of
neighboring coveys.
TABLE 14. TERRITORY NO. 13
First count
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
8 on Jan. 4
10 on Dec. 21
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
13 on Oct. 21
Territory vacant
18 on Oct. 14
15 on Dec. 24
Final count
PRAIRIE DU SAC, WIS.
0 before Feb. 15
11 on Feb. 9
0 by Nov. 7
during winter
First count
8 on Jan. 3
Territory not occupied
23 on Jan. 10
12 on Nov. 26
24 on Oct. 31
17 on Nov. 24
TERRITORY NO. 14
Winter fluctuation between 8 and 12
4 on Mar. 1
Probably predation
J
Territory number 13 (table 14) is the sort of territory that
may or may not remain occupied, depending largely upon the
attractiveness of adjacent territories. In common with the
territory number 12, it was essentially occupiable (except for
the last season), however, in contrast with the lethal territory
number 14 (table 15). Roadside debrushing at a strategic place
near a farmyard in 1933-34 probably made the territory lethal
for the following winter, when birds were forced into the farm-
yard to feed.
TABLE 15.
Cause of difference
Egress into better
territory
Final count
0 by Mid-Jan.
Influx; no mortality
Egress to adjacent
territory
2 on Mar. 23
0 by Jan. 3
0 by Mar. 22
0 by Feb. 21
PRAIRIE DU SAC, WIS.
Cause of difference
Egress
ܝ


Predation
Predation
Largely predation
Egress and unknown
The lethal territory number 14 (table 15) is the best example
of its kind that we have of environment incapable of wintering
quail, yet inviting enough to attract unfavorably situated birds
to their almost certain doom. The deficiency seems to be one of
cover; and while the major proportion of the mortality suffered
may be traced to predation, the kinds and numbers of predators
have apparently had little influence. The coveys occupying this
territory are evidently vulnerable to predation by reason of

341
their insecurity of position. Few predators or many predators,
the territory in its present state is not habitable for bob-whites
in winter.
TABLE 16.
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
TERRITORY NO. 15
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count
1
Territory not occupied
ļ
16 on Dec. 22
Territory not occupied
Territory not occupied
16 on Nov. 21
16 on Nov. 10
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count 1
Territory not occupied
14 on Dec. 22
14 on Dec. 9
13 on Dec. 9
12 on Dec. 6
17 on Dec. 1
Final count
12 on Feb. 1
PRAIRIE DU SAC, WIS.
16 on Mar. 31
12 on Mar. 18
The data for territory number 15 (table 16) for 1933-34
(recorded in the field notes but too complicated to be shown
in the table) indicate that the normal carrying capacity is in
the vicinity of 16 and that losses from predators occurred cor-
responding to the number of birds which came in to exceed
that figure-8 birds influx and loss during the season. This
territory and number 16 as well should be considered one of
the number 6 group (table 7).
TABLE 17. TERRITORY NO. 16- PRAIRIE DU SAC, WIS.
Final count
Cause of difference
TABLE 18. TERRITORY NO. 17
M
10 on Feb. 1
9 on Mar. 16
11 on Apr. 1
0 by Feb. 10
10 on Feb. 12
First count
Territory not occupied
20 on Dec. 22
33 Mid-Dec.
23 on Dec. 20
19 on Dec. 10
10 on Dec. 3
¦
Cause of difference
Final count
Egress
I
Territory number 16 (table 17) was not occupied during the
season of 1929-30 because the population had not recovered
sufficiently from the 1928-29 starvation mortality to fill it up.
In 1933-34, the covey of 12 seemed to have moved out by Feb.
10 of its own volition; it was not known to have suffered mor-
tality prior to its egress. In 1934-35, there was much shifting
and temporary invasion by outside birds [Errington (32)].
20 on Mar. 30
33 on Mar. 23
24 on Mar. 22
14 on Mar. 31
11 on Mar. 25
Loss of 8 newcomers
from predation. See text
Egress to No. 19
Predation
Predation
Predation
Probable egress
Probable predation
PRAIRIE DU SAC, WIS.
Cause of difference
No loss
No loss
Influx 2; mortality of 1
Predation
Influx
<
As was the case for territory number 16, territory number 17
(table 18) was unoccupied during 1929-30, the first season after
the catastrophic winter of 1928-29. Thereafter it was occupied,

342
but at first glance one may suspect not up to full carrying
capacity, as only a single bird was lost from predation in the
following three winters. (The data should be considered not
from territory number 17 alone but collectively from the com-
bined adjacent territories of number 4, number 17, number 18
and number 19-see table 22.) Then, by Dec. 18, 1933, the
CWA roadside debrushing crews had destroyed the principal
cover in the territory and had thus forced the resident covey in-
to a precarious existence during which the birds found their
chief refuge in a farmyard, in a cement culvert, and in the open
weedy and stubble growths of fields. In 1934-35, the territory
was occasionally visited by birds from the now over-populated
number 4.
TABLE 19. TERRITORY NO. 18 — PRAIRIE DU SAC, WIS.
Final count
Cause of difference
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
TABLE 20. TERRITORY NO. 19 - PRAIRIE DU SAC, WIS.
Final count
Cause of difference
TABLE 21.
First count
Territory not occupied
Territory not occupied
20 on Dec. 18
27 on Nov. 9
25 on Jan. 9
14 on Jan. 10
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
16 on Mar. 17
20 on Apr. 1
20 on Mar. 19
0 by Jan. 30
First count
Territory not cccupied
24 on Dec. 22
Territory not occupied
Territory not occupied
22 on Dec. 8
20? by Dec.
20 on Feb. 1
0 by Mid. Jan.
25 by Mar. 18
Predation
Predation
Predation
Egress
Territories number 18 and number 19 (tables 19 and 20),
while distinct, are adjacent and may be considered more advan-
tageously as common ground for the coveys resident: (table
21).
20 on Feb. 1
16 on Mar. 17
20 on Apr. 1
20 on Mar. 19
25 by Mar. 18
Predation
•
Mainly egress into num-
ber 18
Influx from number 15
COMBINATION OF TERRITORIES NO. 18 AND NO. 19.
First count
Final count
Cause of difference
Territory, not occupied
24 on Dec. 22
20 on Dec. 18
27 on Nov. 9
25 on Jan. 7
34 in Dec.
Predation
Predation
Predation
Predation
Egress; some influx
In combination, then, territories number 18 and number 19
(table 21) present more of a unified picture of winter bob-
white survival than either one alone. Combined with the
adjacent territories number 4 and number 17 of the same
natural group, they present a picture still more unified and one
343
that reveals a surprising definiteness of year to year carrying
capacity, not so much for an individual territory but for the
group of territories constituting the common range of the resi-
dent winter population: (table 22).
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
TABLE 22. COMBINATION OF TERRITORIES
NO. 4, NO. 17, NO. 18 AND NO. 19.

Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count
15 on Jan. 4
64 on Dec. 22
72 by Dec.
68 by Dec.
68 by Dec.
91 by Dec.
The tract of land making up the combined covey territories
number 4, number 17, number 18 and number 19 (table 22) was,
of course, under-populated in 1929-30, the first season following
the starvation mortality of 1928-29; in fact, territory number 4
was the only one of this group to have a wintering covey for
that season. Survivals for the next three winters showed a fair
degree of constancy, namely 60, 64 and 59. The lower survival
of 51 for 1933-34 is entirely to be expected in view of the whole-
sale removal of brushy vegetation along the roadsides in con-
nection with CWA unemployment relief activities. In 1934-35,
the survival was probably somewhat higher than it would have
been except that one of the principal coveys was situated near
territory number 15, which it partially shared to convenient
advantage.
TABLE 23. TERRITORY NO. 20 -
Season
1932-33
1933-34
1934-35
Final count
14 on Feb. ió
60 by Mar.
64 by Mar.
59 by late Mar.
51 by late Mar.
59 by late Mar.
First count
Territory not occupied
Territory not occupied
25 on Jan. 10
28 on Dec. 12
Final count
First count
11 ? on Dec. 18
5 on Jan. 8
4 on Jan. 4
PRAIRIE DU SAC, WIS.
21 on Mar. 19
22 on Mar. 23
Territory not regularly occupied
18 on Nov. 14
0 by Dec. 24
Cause of difference
Probably predation
Predation
Predation
Predation
Predation
Predation and egress
Egress to number 13
Although territory number 20 (tablę 23) is not a choice
territory, the survival of 21 for the season of 1931-32 and of 22
for 1932-33 hints a substantial carrying capacity for favorable
years. During 1933-34, the territory was not occupied by a
truly resident population but was split into a number of partial
covey ranges. In 1934-35, the food supply was too short to hold
the birds later than December. They then moved to a portion
of territory number 13 (table 14) which proved to be lethal for
the season.
M
TABLE 24. TERRITORY NO. 21 FT. DES MOINES, IOWA.
Cause of difference
Final count
5 on Mar. 5
5 on Feb. 27
15 on Feb. 8
Predation
Predation

Cause of difference
Egress
No loss
Influx
344
Territory number 21 (table 24) may perhaps be only a part
of a larger territory, but it seems to show sufficient identity of
its own to be considered separately. The heavy survival figure
of 1934-35 was due mostly to a strong late influx.
TABLE 25. TERRITORY NO. 22— FT. DES MOINES, IOWA.
First count
Final count
Cause of difference
17 on Feb. 27
15? Dec. 11
16? Jan. 4
15 on Feb. 8

Season
1933-34
1934-35
Season
1932-33
1933-34
1934-35
TABLE 26. TERRITORY NO. 23 — DES MOINES, IOWA, WATERWORKS
SUPPLY GROUNDS (WILD LIFE REFUGE).
First count
20 on Dec. 16
12 on Dec. 8
19 on Nov. 23
Season
1932-33 1
1933-34
1934-35
Season
1932-33
1933-34
1934-35
Final count
0 by Mar. 20
0 by Feb. 27
0 by Feb. 9
?
First count
Territory not occupied
18 on Jan. 12
12 on Nov. 23
Predation

Territory number 23 (table 26) was attractive enough to
hold quail only during the first half of winter; thereafter, the
birds shifted to more favored adjacent territories (for example,
number 10), even though they were well situated and relatively
undisturbed. There was nothing perceptibly wrong with the
territory, yet the birds left. Possibly number 23 may be more
correctly thought of as a part of number 10 and number 24.
14 by Feb. 27
0 by Dec. 4
Cause of difference
—
TABLE 27. ·
TERRITORY NO. 24 DES MOINES, IOWA,
WATERWORKS SUPPLY GROUNDS.
Final count
Egress
Egress
Egress
Cause of difference

| Mainly egress
Egress; no food
Territory number 24 (table 27) is not habitable under
present conditions without winter feeding. In 1933-34, the
establishment of feeding stations resulted in the secure accom-
modation of a covey of quail. The feeding was not continued
the following season, and the covey present in early winter
soon had to leave.
TABLE 28. TERRITORY NO. 25 — AMES, IOWA.
First count
Final count
20 on Dec. 14
0 by Feb. 12
15 on Jan. 14
0 by late Jan.
Territory not occupied
Cause of difference
| Largely egress
| Egress
Territory number 25 (table 28) is plainly not choice
environment. The departure of the occupying coveys for 1932-
33 and 1933-34 may signify lack of habitability. That it was
not occupied in 1934-35 may not be so significant, as the quail
population was too low that season to fill up territories of
known superior quality.

345
Season
1932-33
1933-34
1934-35
Season
1932-33
1933-34
1934-35
TABLE 29.
Season
1932-33
1933-34
1934-35
TERRITORY NO. 26
First count
38 on Nov. 25
30 on Jan. 16
26 on Dec. 14
First count
11 on Nov. 26
14 on Jan. 18
11 on Nov. 22
S
Final count
36 on Mar. 22
0 by Feb. 27
2 by Mar. 9
In 1933-34, the apparent egress from territory number 26
(table 29) seemed at least partly compensated by an influx into
territory number 28 (table 31). We don't know what happened
in 1934-35, but we are very sure that the losses from predation
were light; birds seemed merely to disappear, usually in small
groups (egress of 10 of the last 12 birds was rather definitely
traced, however). [Errington (32)].
TABLE 30. TERRITORY NO. 27
Final count
11 on Mar. 21
0 by Feb. 27
5 by Jan. 23
First count
14 on Jan. 7
38 on Jan. 14
15 on Nov. 24
TABLE 31. TERRITORY NO. 28
AMES, IOWA.
Cause of difference
G
| Possibly predation
Apparently egress
Apparently egress
|
The shrinkage of the covey occupying territory number 27
(table 30) in 1934-35 was gradual and exceedingly baffling.
Despite very careful search no sign of mortality could be found.
The territory was situated in close proximity to a settlement
of squatter's shacks, and some losses may have been due to
poaching by the hunters who were constantly in evidence.
AMES, IOWA.
Cause of difference
| No loss
Apparently egress
| Unknown
AMES, IOWA.
Final count
Cause of difference
13 on Mar. 20
Probably predation
31 ? on Feb. 27 | Some predation
Birds did not stay
The population of number 28 (table 31) for 1933-34 appear-
ed to be partly composed of birds also ranging in territories
number 25 and number 26. This season, the food supply was
much superior to that of the surrounding territories, and
resulted in an exceptional concentration of birds during the
greater part of the winter. Whether the subsequent egress of
the birds of number 26 had any relation to the concentration
at number 28 is hard to say. For all of the territories number
25 to number 28, the data may be said to be generally inade-
quate to justify any conclusions as to carrying capacity.
SURVIVAL DATA-THIRD CLASS
(Data differ from those of Classes One and Two chiefly in that
emergency starvation losses complicated efforts to determine carrying
capacities of the respective territories; these territories of Class Three
were similarly bounded by barriers or by territories kept under con-
temporaneous observation, as were the territories of Classes One and
Two.)

346
TABLE 32. TERRITORY NO. 29 · PRAIRIE DU SAC, WIS.
Final count
Cause of difference
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count
Territory not occupied
16 on Dec. 23
24 on Nov. 16
22 on Dec. 18
11 on Oct. 23
27 on Nov. 14
Season
1929-30
1930-31
1931-32
13 on Feb. 28
12 on Apr. 6
17 on Mar. 23
TABLE 33.
8 on Feb. 27
16 on Mar. 22
First count
18 on Jan. 25
Territory unoccupied
10 on Jan. 5
Predation; 1 collected
Egress; predation and
starvation
The 1930-31 survival of territory number 29 (table 32)
should have been 14, as one bird was collected late for exam-
ination. The survival for 1931-32 was doubtless somewhat
below normal by reason of the loss of a few birds from late
winter starvation (from Jan. 16 until March the population had
been 18 birds). The 1933-34 covey of 11 lost no birds until the
food situation became acute about mid-February, which indi-
cates an intrinsic security of population from predation at this
level.
Predation and food
shortage
Predation and food
shortage
Probably predation

Taking into account the losses occasioned by late winter
starvation and the apparent vulnerability to, and the security
from, predation of the wintering birds at different population
levels, we may then say that the normal carrying capacity for
territory number 29 seems to be between 14 and 17, probably
nearer the latter number.
TERRITORY NO. 30 — PINE BLUFF, Wis.
Final count
5 by Mar. 3
| Starvation
16 on Mar. 22 | See text
The data from territory number 30 (table 33) are too
heterogeneous to be expressed well in tabular form, although
they are of reliable quality. The territory is sufficiently mar-
ginal to be subject to unpredictable influx, egress and emer-
gency losses; yet under open winter conditions, it seemed to
have a carrying capacity of about 16 birds for the two seasons
occupied.
A
Cause of difference
-
In 1929-30, the loss of 13 out of 18 was practically all due to
starvation (except for two birds killed by predators). A sub-
sequent March influx of 18 from the adjacent fortuitous terri-
tory number 61 (see table 65 and discussion), after food had
been made available through melting of the snow, was fairly
well accommodated. Territory number 30 was not completely
abandoned in 1930-31, but was visited only occasionally by a
covey from number 34.
The history of the wintering population for 1931-32 is rather

347
involved. By Jan. 30, a covey of 20 had joined the 10 already
resident, to depart for the emergency territory number
58 by Feb. 3. The covey of 10 had also gone to number 58
by March 2. By March 15, the 19 survivors in territory number
58 had returned to number 30, where they were still insecure
enough to lose 3 more from predation by March 22.
TABLE 34.
TERRITORY NO. 31 - HONEY CREEK BOTTOMS, WIS.
Season
1929-30
1930-31
1931-32
TABLE 35.
Season
1929-30
1930-31
1931-32
Season
1929-30
1930-31
1931-32
First count
17 on Jan. 4
Territory not occupied
16 on Dec. 7
Season
1929-30
1930-31
1931-32
First count
20 on Jan. 4
23 on Nov. 25
20 on Dec. 3
1
Final count
12 on Feb. 16
I
13 on Mar. 23
TERRITORY NO. 32 - HONEY CREEK BOTTOMS, WIS.
P
The adjacent territories number 31 and number 32 (tables
34 and 35) were commonly too deficient in food to be regularly
habitable during periods of snow. During open winter weather,
the birds were securely situated, so far as predators were con-
cerned; and the carrying capacities for the territories were
probably not far from the number usually beginning the winter,
or about 16 for number 31 and about 20 for number 32.
TABLE 36. TERRITORY NO. 33-PINE BLUFF, WIS.
First count
25 on Jan. 23
13 on Dec. 20
20 on Jan. 4
Cause of difference
Final count
0 by Feb. 16 | Starvation
19 by Feb. 9
0 on Mar. 23 | Egress
Final count
11 on Feb. 12
11 on Feb. 12
12 on Mar. 4
| Starvation
| Apparently storm
<
TABLE 37. TERRITORY NO. 34 -
First count
Final count
Territory not occupied
21 on Dec. 20
The territory number 33 (table 36) survival of 11 for 1929-
9, compared with the 11 and 12 survivals for the next two
seasons, may not have the significance apparent at first glance,
because of the probable role of emergency losses reducing the
population to this level. This territory seems to be somewhat
submarginal in quality or at least in attractiveness, for the sur-
viving populations in all three instances moved out toward the
end of the winter after the dates given in the table. Territory
number 33 belongs in about the same category as number 30,
subject to the same likelihood of sudden influx, egress, or
emergency mortality, but it probably has a carrying capacity
not far from the 11 or 12 indicated.
Cause of difference
21 on Feb. 8
18 on Jan. 27 1 10 on Mar. 22
Cause of difference
Mainly starvation
| Predation
| Unknown
PINE BLUFF, WIS.
Cause of difference
No loss; see text
| Starvation
348
The primary weakness of territory number 34 (table 37) is
that, while there is a food supply sufficient for open winters (as)
1930-31), it is unavailable during periods of heavy snow. Dur-
ing the first season (1929-30), the covey which should logically
have occupied this territory stationed itself in a territory (num-
ber 61) used only the one season, but made temporarily
attractive by a farmer spreading grain-bearing manure in the
fields; toward the end of the winter it moved in to repopulate
the starvation-depleted territory number 30.
For 1930-31, there was no starvation loss for the sole reason
that not enough snow fell, or remained, to keep the food on
the ground covered; in 1931-32, a comparatively brief period of
crisis was attended by wholly expected mortality. For open
winters, the carrying capacity of the territory seems to be in
the vicinity of 20 birds.
SURVIVAL DATA-FOURTH CLASS
(Data reliable as to accuracy of counts unless otherwise indicated but
of less reliability than Classes One to Three because of the nearness of
uncensused coveys to those under regular observation; data may also be
complicated by starvation emergencies but are commonly not. In
short, the territories in this class are those located at the edges of
observational areas.)
TABLE 38. TERRITORY NO. 35
Season
First count
Territory not occupied
1929-30
1930-31
7 on Dec. 23
1931-32
18 on Dec. 3
1932-33
21 on Dec. 2
1933-34
5 on Nov. 23
1934-35 1 14 on Dec. 7
1
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
PRAIRIE DU SAC, WIS.
Final count
7 ? on Mar. 30 | No apparent loss
16 on Feb. 16
See Text
19 on Mar. 22
See Text
4? on Jan. 18
See Text
14 on Mar. 22 | See Text
TABLE 39. TERRITORY NO. 36-
Cause of difference
|
Sp
|
During the seasons of 1931-32, 1932-33 and 1934-35, territory
number 35 (table 38) was the partial range of an uncensused
covey just outside of the observational area. Interchange occur-
red at times but to what extent is unknown. For the season of
1933-34, the territory seemed to be left largely to the small
covey of 5, the survivors of which left the territory in late.
January.
NAKOMA, WIS.
-

First count
Final count
8 on Nov. 4
0 by Dec. 1
About 15 during winter (Dickson)
About 18 during winter (Dickson)
8 on Feb. 3 I 10 by Mar. 29 | Influx
About 10 during winter (Dickson)
About 15 during winter (Dickson)
Cause of difference
Egress

In contrast with the situation in many of the Prairie du Sac
territories, there was no evident under-population of bob-
349
whites in the Nakoma-Wingra Refuge area during the winter
of 1929-30. Birds were in the vicinity but apparently did not
find territory number 36 (table 39) wholly to their liking.
Territory number 36 owes whatever habitability and attrac-
tiveness it has largely to a supply of corn and barley which is
kept beside a marsh for the feeding of a population of semi-
domesticated wild mallard ducks. Both quail and ducks have
used one main heap of piled grain as a common feeding place.
A variable number of pheasants also have used the grain pile.
It may be no more than coincidence that the quail used this
territory in the smallest numbers during two seasons (1929-30
and 1933-34) when the wintering flock of ducks was the
largest. Table 40 is based upon the combined notes of Erring-
ton and Dr. J. G. Dickson (University of Wisconsin).

Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
115
35
TERRITORY NO. 36
TABLE 40.
Mallard, Av. Pop. | Pheasant, Av. Pop.
100
6 ?
65
85
70
Season
1929-30
1930-31
1931-32
1932-33
NAKOMA, WIS.
10
15
12
15
20
Bob-white, Av. Pop.
0 except early
15
18
The numbers given for mallards and pheasants are approxi-
mate rather than exact, but they are considered quite reliable;
the numbers for quail less reliable, except those from 1929-30
and 1932-33. Altogether, we are not at all sure that these limit-
ed data have any real territorial significance. They seem to
hint faintly that quail may tend to avoid mounting numbers of
conspicuous birds or that their own security may be lessened
by concentrations of conspicuous species occupying the same
range.
First count
13 on Nov. 5
25 on Jan. 6
35 on Dec. 9
Territory not occupied
8 to 10
The above may appear to be just another expression of the
commonly held ideas relative to the effect of heavy densities.
of "buffer" species attracting predators, with consequent losses
to quail. We do not believe, however, that the explanation (if
there is one, or if there is anything to explain) is as simple as
that. The influence of "buffer" populations on winter quail
losses from predation seems not too clear [see Errington (26)
and discussion later in this bulletin].
Final count
20 on Mar. 2
28 on Mar. 17
0 by Jan. 3
10
15
TABLE 41. TERRITORY NO. 37 — UNIVERSITY HILL FARM,
MADISON, WIS.
Cause of difference
| Influx
Influx from No. 3
| Eviction by pheasants
350
By March 23, 13 of the 1929-30 population of territory num-
ber 37 (table 41) had moved to the lately vacant territory num-
ber 3 (table 3). The territory was not occupied during the
season of 1932-33 because of food shortage due to agricultural
practices.
The evident abandonment of the territory to ring-necked
pheasants in 1931-32 is significant. Most of the pheasants in
the entire University Hill Farm area were localized about terri-
tory number 37, but not until 1931-32 did they congregate in
sufficient densities to bring about a recognized eviction of the
quail [Errington (20)]. The quail simply seemed to leave when
the pheasants became too numerous; no actual strife between
the two species was noted.
TABLE 42. TERRITORY NO. 38 — PRAIRIE DU SAC, WIS.
Final count
21 on Mar. 11
44 on Mar. 25
21 on Mar. 15
21 on Feb. 9
0 by Mar. 25
Season
1931-32
1932-33
1933-34
1934-35
First count
23 on Jan. 8
49 on Dec. 16
25 on Jan. 5
Season
1931-32
1932-33
1933-34
1934-35
27 on Nov. 20
1
1
I
First count
24 on Jan. 11
13 on Dec. 16
28 on Oct. 21
34 on Nov. 12
Cause of difference
The uniformity of survivals for 1931-32 and 1933-34 may
indicate that 21 is not far from the real carrying capacity of
territory number 38 (table 42). In 1934-35, the survival by Feb.
9 was 21; then a severe blizzard apparently wiped out the
whole population. The higher survival for 1932-33 may point
to the presence of an unobserved territory immediately outside,
of territory number 38, which in combination with number 38
may be able to accommodate a greater number of birds than
number 38 alone. Were this latter the case, then it would not be
beyond reason to postulate that the quail population occupying
the combined territories may have found it advantageous to
spend the season of 1932-33 mainly in territory number 38
instead of in smaller numbers both in territory number 38 and
in the adjacent but uncensused territory outside of the obser-
vational area. In that event, the situation would not differ
materially from that described in connection with the combina-
tions of territories number 6, number 54 and associated terri-
tories number 12, number 15 and number 16.
TABLE 43. TERRITORY NO. 39 — PRAIRIE DU SAC, WIS.
Final count
8 on Mar. 21
11 on Mar. 25
22 on Mar. 27
0 by Mar. 6
I
Predation
Predation
Predation
Mainly blizzard mortality...
Cause of difference
| Starvation
|
S


Probably predation
Probably mainly predation
Predation; egress
| starvation

351
Territory number 39 (table 43) was also located on the
extreme edge of an observational area, with uncensused terri-
tories immediately beyond. During 1933-34, in particular, fluct-
uations in numbers of the wintering quail were noted, doubtless
on account of interchange with coveys outside. There was
considerable shifting in 1934-35, with as many as 42 birds pres-
ent at once, but the late February blizzard brought heavy
mortality and drove out those it didn't kill.
Season
1929-30
1931-32
1932-33 T
!
Season
1929-30
1930-31
1931-32
TABLE 44. TERRITORY NO. 40 — PINe bluff, wIS.
Final count
First count
Territory not occupied
11 on Dec. 20 I
19 on Feb. 3
1
Nothing is known of the territories adjacent to number 40
(table 44) but outside of the observational area.
First count
0 by Jan. 23
25 on Dec. 20
34 on Jan. 4
Season
1931-32
1932-33
1933-34
1934-35
TABLE 45. TERRITORY NO. 41 -
Gjaldg
Final count
See Text
23 on Mar. 16
39 on Mar. 22
10 on Mar. 16
17 on Mar. 4
Season
First count
1930-31 | 15 on Nov. 15
1931-32 1 15 on Dec. 11
|
Cause of difference
Probably predation
| Predation
PINE Bluff, wis.
Territory number 41 (table 45) was first visited on Jan. 23,
1930, at which time it was ascertained that the population form-
erly occupying it had moved into territory number 33, there to
mingle and starve with the other birds.
The population of 1930-31 may be fairly near carrying
capacity, as the higher levels of 1931-32 lost at a rather high
rate from predation, even before the late February or early
March influx of 12 from the adjacent territory number 33.
C
Cause of difference
Final count
20 on Mar. 19
8 on Mar. 20
| Predation
|
TABLE 46. TERRITORY NO. 42— MAZOMANIE, WIS.
Influx 12; Predation 7

The 1931-32 population of territory number 42 (table 46)
had gained 6 birds by influx by Jan. 7, and these apparently
were accommodated with security until the cataclysmic star-
vation emergency of early March [Errington (20)].
Cause of difference
| Influx; 1 collected
Starvation; See text
TABLE 47. TERRITORY NO. 43 - MAZOMANIE, WIS.
First count
Final count
17 on Jan. 9 I 17 on Mar. 20
About same number
No data
data not exact
15 on Feb. 1
Cause of difference

No loss
18? on Mar. 26 | Influx of about 5 by Feb. 5
352
The 1934-35 figures for territory number 43 (table 47) were
contributed by Arthur Hawkins who had been carrying or
survival studies of bob-white populations on several southern
and central Wisconsin observational areas, under direction of
Prof. Aldo Leopold of the University of Wisconsin. It so hap
pened that Mr. Hawkins had 1934-35 data on this territory
which had been formerly studied by Errington.

TABLE 48. TERRITORY NO. 44 - UNIVERSITY HILL FARM,
MADISON, WIS.
Season
1929-30
1930-31
1931-32
1932-33
First count
10 on Dec. 20
Territory not occupied
10 on Jan. 9
10 on Jan. 27
TABLE 49.
Season
1930-31
1931-32
TERRITORY NO. 45
First count
29 on Dec. 14
37 on Dec. 9
Final count
0 by Mar. 2
The 1931-32 starvation crisis for territory number 44 (table
48) arose largely as the result of competition with ring-necked
pheasants for food. The egress of 1932-33 was likewise due to a
food shortage caused, in this instance, by the agricultural
practices discussed under territory number 3.
4 on Mar. 19
0 by Feb. 8
First count
25 on Dec. 24
35 on Dec. 3
C
Cause of difference
| Egress
Starvation and egress
Egress (See text)
Final count
26 on Mar. 29
25 on Mar. 16
LAKE WINGRA, MADISON, WIS.
Cause of difference
Predation
See text
The survivals of 26 for 1930-31 and of 25 for 1931-32 on
territory number 45 (table 49) have a deceptive similarity at
first gi nce, but in actuality most of the mortality for 1931-32
may be attributed to a March blizzard. Had it not been for this
late season emergency loss, the survival for 1931-32 would
probably have been in the vicinity of 35, which would indicate
not definiteness of normal carrying capacity but lack thereof
It by no means follows, however, that the combination of
territory number 45 and adjacent uncensused territories outside
of the area might not have a more definite carrying capacity,
even if number 45 alone has not. The possibility of this being
true is well demonstrated by the data from territories number
4, number 17, number 18 and number 19 (table 22) when consid-
ered separately and in the aggregate.
TABLE 50. TERRITORY NO. 46 — HONEY CREEK BOTTOMS, WIS.
Season
Final count
Cause of difference
Probably predation
24 on Mar. 15
1930-31
1931-32
18 on Mar. 23 | Egress

Insofar as the coveys wintering in territory number 46
(table 50) suffered little or no loss from predation at any of the
densities recorded, it is apparent that the maximum carrying
capacity for the territory is near 35 birds or higher. Even the
353
egress of about half of the population in 1931-32 took place
practically at the end of the winter and was not forced in any
perceptible way. Much uncensused but occupied quail range
abutted territory number 46 on three of its four sides.
Season
1929-30
1930-31
Season
1929-30
1930-31
TABLE 51. TERRITORY NO. 47 - MC FARLAND, WIS.
First count
Final count
27 on Dec. 7
21 on Dec. 27
19 on Mar. 24
20 on Feb. 19
The presence of neighboring uncensused territories rule
territory number 47 (table 51) out of Class One, but it was
probably isolated enough to be entitled to consideration as a
definite unit.
Season
1932-33
1933-34
1934-35
TABLE 52.
Season
1932-33
1933-34
1934-35
1
First count
33 on Dec. 17
40 on Nov. 3
TERRITORY NO. 48-MADISON, WIS.
Eight birds were collected for examination from territory
number 48 (table 52), and probably some others died from
incidental shot wounds by Jan. 10. Fairly heavy pressure from
enemies was noted during fall and winter, but it is very difficult
to judge whether most of the loss from predation took place
before or after the shooting. If most of the predation occurred
before the population had been reduced by the shooting, then
the carrying capacity of the territory would appear to be about
30 birds.
1
First count
13 on Dec. 14
No data
11 on Feb. 4
TABLE 53. TERRITORY NO. 49 BOONE, IOWA.
Final count
11 on Mar. 20
Cause of difference
¡Predation
|_ Probably predation

Final count
31 on Feb. 7
24 on Jan. 10
First count
9 on Dec. 14
No data
11 on Feb. 4
I
Cause of difference
Probably predation
Predation and collecting

11 on Mar. 2
Territory number 49 (table 53) is probably a distinct terri-
tory, though insufficient work was done on the surround-
ing lands to warrant placing it in Class One. Logan J. Ben-
nett carried on the chief observational work on the Boone
territories for the season of 1932-33.
Cause of difference
Probably predation
TABLE 54. TERRITORY NO. 50 — BOONE, IOWA.
Final count
8 on Mar. 20
No loss
Cause of difference
Probably predation
10 ? on Mar. 2 | Predation
354
Season
1932-33
1933-34
1934-35
Season
1931-32
1932-33
TABLE 56. TERRITORY NO. 52
TABLE 55. TERRITORY NO. 51
TERRITORY NO. 51 - BOONE, IOWA.

First count
30 on Dec. 14
No data
18 on Dec. 18
Territories number 50 and number 51 (tables 54 and 55)
were situated in the bottom lands of the Des Moines River
adjacent to other territories not kept under observation but
unquestionably occupied. Hence, we have no way of determin-
ing the extent to which interchange between censused and
uncensused coveys may have taken place, or what proportion
of a common population range may have been represented by
the observed territories.
Season
1925-26
1926-27
1927-28
1928-29
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
First count
10 in Feb.
11 on Dec. 16
VICINITY OF 37th ST. AND UNIVERSIT Y
AVENUE, DES MOINES, IOWA.
Final count
25 on Mar. 20 | Predation
16 on Mar. 20 | Predation; loss of 1
M
Cause of difference

First count
Final count
7 by April
10 on Mar. 20
Certain of the residential sections of Des Moines furnish
regular wintering territories for bob-white coveys. The birds
have access to good cover in the wooded ravines of many
backyards and they feed largely in gardens or at stations main-
tained for them. For the 1931-32 figures of territory number 52
(table 56) we are indebted to the notes of Mrs. John E. Stewart;
these birds represented a covey which frequented her back-
yard and which were especially convenient for study [Erring-
ton (24)]. The apparent egress of 3 birds by April was attrib-
uted to restlessness attending the approach of the breeding
season.
Dr. H. H. Knight, of Iowa State College, has since 1925 kept
notes on the quail frequenting his backyard at 133 South River-
side, Ames, Iowa. His survival and wintering notes are here-
with condensed for examination (table 57).
Cause of difference
Probably egress
Probably egress
TABLE 57. TERRITORY NO. 53 — AMES, IOWA.
Final count
16 by Feb.
16 by Oct.
16 by Oct.
16 by Feb.
17 by Oct.
No apparent loss during winter
11 by Feb.
13 on Sept. 15
No fall count
Exact territory not
15 on Jan. 20 1
Territory occupied by 14 or 15 but notes not kept
11 by Jan. 11
occupied; see text
15 on Mar. 6 I
14 by Dec.
No apparent loss during winter
13 on Dec. 15
0 by Jan. 7
Cause of difference

Disappeared;
possibly trapped
1
355
Dr. Knight's notes (table 57) point to a gradual decline
in carrying capacity or local environmental attractiveness
beginning about 1928. The decline was probably not as abrupt
as the impression from the 1928 to 1931 figures may at first
indicate; in actuality, during these three seasons when there
were fewer quail recorded in the immediate vicinity of the
Knight home, there were more quail noted in the general
neighborhood.
In 1928-29, a covey of 14 ranged not far distant in territory
not known to have been occupied previously. In 1929-30, we
suspect that there may have been a similar distribution, though
it is not mentioned in the notes. The summer of 1930 was very
dry, and in August fire swept the territory, ruining it for winter
occupancy by quail; there were noted on Dec. 15, however,
coveys of 11 and 16 in a cornfield to the south, which may
correspond to those presumably evicted by the fire.
SURVIVAL DATA-EMERGENCY TERRITORIES
(Data from territories usually occupied but one season out of three to
six and then only because of apparent necessity; the territories were
usually deficient in cover although possessed of enough food to attract
coveys evicted by agricultural practices, coveys crowded out of regular
habitats by excessive densities of their own species or by other species
such as pheasants, or coveys forced into precarious situations by
hunger.)
TABLE 58. TERRITORY NO. 54 -
Season
1931-32
1934-35
First count
26 on Dec. 17
24 on Dec. 15
Season
1933-34
T
PRAIRIE DU SAC, WIS.

First count
17 on Nov. 21
Final count
19 on Mar. 5
12 on Mar. 18
Territory number 54 (table 58), while occupied but two out
of the six seasons it has been observed, nevertheless represents
fairly habitable quail range. It may be recalled from the discus-
sion under territory number 6, that territory number 54 may be
looked upon as something of an offshoot, the occupancy of the
latter being forced by overcrowding of the favored territory
number 6. In 1934-35 the continued occupancy of number 15 at
a point very close to number 6 probably lowered the carrying ·
Capacity of both number 6 and number 54.
d
Cause of difference
Predation and poaching
| Predation
TABLE 59. TERRITORY NO. 55 -
TERRITORY NO. 55 - PRAIRIE DU SAC, WIS.

Final count
Cause of difference
12 on Feb. 10 | Predation
Territory number 55 (table 59) was vacated by the surviv-
ing 12 after Feb. 10. It was occupied one season out of six.
356

TABLE 60. TERRITORY NO. 56
Season
1933-34
Season
1929-30
First count
22 on Dec. 8
Season
1931-32
T
Season
1931-32
PRAIRIE DU SAC, WIS.
Final count
The 7 birds surviving in territory number 56 (table 60) by
Jan. 9 joined the population occupying the adjacent territory
number 18, thereby bringing about an over-populated condition
for that territory as well. Prior to the influx of the 7 from terri-
tory number 56, territory number 18 had had but 18 birds which
it apparently was accommodating without difficulty; within
approximately a month after the seven had joined, four bird's
were lost, and later one more, bringing the total surviving in
territory number 18 down to 20 by March 19.
7 on Jan. 9
Cause of difference
Predation and egress

TABLE 61. TERRITORY NO. 57 — MC FARLAND, WIS.
First count
6 on Dec. 6
Final count
0 by Jan. 13
The birds simply starved out of territory number 57 (table
61) during the season of 1929-30, but quail made no known
attempts to occupy it during the following season, despite a
visibly better food supply.
Cause of difference
Starvation

TABLE 62. TERRITORY NO. 58- PINE BLUFF, WIS.
First count
31 on Jan. 27
Final count
Cause of difference
19 on Mar. 15 | Largely predation
Territory number 58 (table 62) is comparable to territory
number 54 in that it could be described as something of an off-
shoot of the more favored territory number 30. It, too, seemed
to be fairly habitable—at least in the one out of three seasons it
was known to be occupied-but the common range represented
by number 58 and the adjacent number 30 was plainly over-
populated. (For an account in more detail, see text for terri-
tory number 30.)
TABLE 63. TERRITORY NO. 59 PINE BLUFF, WIS.
First count
17 on Jan. 5
Final count
12 on Mar. 15

Cause of difference
Probably predation
Territory number 59 (table 63) was occupied one out of
three seasons. It may be compared to a small island of passably
habitable environment surrounded by extensive spaces uncon-
genial-for wintering quail. The food and cover combinations
were such that the covey frequenting the place in 1931-32 had
few alternative courses of action in the event of attack by
predators and hence was, to some extent, vulnerable.
357
TERRITORY NO. 60 DES MOINES, IOWA,
WATERWORKS SUPPLY GROUNDS.
I
TABLE 64.
Season
I
First count
1933-34 | 7 on Jan. 12
Season
1929-30
Final count
0 by Feb. 27
The small covey of 7 indicated for territory number 60,
(table 64) seemed confined as long as it lasted to a narrow
irregular strip of land bordering and penetrating territories
number 10, number 23 and number 24. We are not at all sure
that we have accurately pieced together the story of what
happened here, but we think that this was a covey forced to
wander from one unsatisfactory covert to another by reason
of the better territories being already occupied to capacity. At
any rate, the most evidence of predation found in the entire
observational area (two kills) was found in territory number
60, and the covey finally disappeared completely.
SURVIVAL DATA-FORTUITOUS OR BUILT-UP
TERRITORIES
Cause of difference
Predation and egress
(Data from territories occupied mainly by coveys establishing and
maintaining themselves by chance or by adaptiveness in places usually
not frequented; data also from usually uninhabitable territories made
habitable through human activities, whether through accident or intent.)
First count
18 on Jan. 25
TABLE 65. TERRITORY NO. 61 PINE BLUFF, WIS.
C
Final count
Cause of difference
0 by Mar. 22 | Egress after Mar. 3
Territory number 61 (table 65) was made habitable for the
one season of the three observed by grain-bearing manure
spread near enough to a grapevine-grown fencerow to be
accessible. The birds wintered from Jan. 25 to Mar. 3 without
loss, but thereafter moved into territory number 30 which had
been virtually depopulated by an earlier starvation crisis.
Territory number 62, at Prairie du Sac, Wis., was occupied
for about the same reason as territory number 61 except that
the quail subsisted on grain which they picked out of hog
manure from a pasture. A covey of 12 was counted Dec. 24,
1929, and it seemed well situated for the winter, although no
exact counts were obtained afterward.
Territory number 63, Pine Bluff, Wis., was made habitable
during 1929-30, one winter out of three, by the dumping of a
lad of grain screenings beside a road at the edge of a woodlot.
When first noticed, Feb. 3, 8 birds were taking advantage of
this very welcome source of food in an area where there was
much starvation. One month later, apparently the same num-
ber of birds were still scratching grain out of the pile.
Territory number 64, Denzer, Wis., was occupied one
season out of three, and then, to appearances, only because a
farmer had left a few corn-bearing shocks near a wooded bluff.

358
On Nov. 30, 1929, a count of about a half dozen was secured;
7 on Dec. 15; no actual counts thereafter, but the "sign" indi-
cated that the covey wintered safely.
Season
1929-30
Season
TABLE 66. TERRITORY NO. 65-PINE BLUFF, WIS.
Final count
First count
13 on Jan. 25
18 on Mar. 27
1929-30
The birds occupying territory number 65 (table 66) showed
exceptional adaptiveness for this locality. This is the only
covey recorded in the Wisconsin notes as having survived in a
corn field territory without brushy cover or without at least
dense marshy growths or weed patches. The birds used partly
open corn shocks-favoring two in particular of the dozen or
more available-in lieu of the usual cover types. That this
brushless environment had a certain temporary attractiveness
is proved by the continued influx of birds during the late win-
ter and the scant evidence of mortality suffered (the only bird
found dead was a traffic victim on an adjacent highway).
It might be remarked parenthetically that the wintering of
quail away from brushy cover is not of such infrequent occur-
rence in central Iowa as it appears to be in southern Wisconsin.
Bob-whites on the more open central Iowa observational areas,
at stable population levels corresponding to those of the semi-
wooded southern Wisconsin areas, doubtless have adapted
themselves to exist with less cover than birds not faced by as
great necessity to do so. Comparatively few Iowa coveys,
nevertheless, have demonstrated any decided ability to thrive
in corn fields devoid of cover other than that furnished by corn-
stalks and weeds or by shocks.
TABLE 67. TERRITORY NO. 66
First count
Final count
21 on Nov. 2
Cause of difference
Influx of 8; some loss
17 on Feb. 1
ROXBURY, WIS.
1
Cause of difference
Probably predation
before Dec. 24
{
Ga

Territory number 66 (table 67) was a farmyard and adjacent
environment. The territory as a whole had been so closely
grazed and so severely debrushed that it could hardly have
been habitable for a covey of less adaptive living routine. As
it was, the birds lived mainly about the farm buildings (ther
favored roost was in a cellar) and about the little brushy cover
still remaining. They were protected and fed, and for a nu-
ber of successive winters the territory had been occupied.
The covey was said to have been wiped out by pot-shooters
late in the winter of 1929-30. At any rate, the birds disappeared
and none were known to have reestablished themselves about
the farmyard by the time that inspections were discontinued (3
years later. There were other occupied territories in the neigh-


359
borhood during the following winters, but no more birds devel-
oped quite the same habit of intimacy with man.
This instance is rather typical of the history of many barn-
yard territories. Commonly, birds are forced by hunger to enter
farmyards presumably strange to them; if they are unmolested
and find an accessible food supply, they doubtless come more
readily the next time a starvation crisis presents itself; finally,
they may simply accept the farmyard as a territory and may
regularly establish themselves there at the time of the fall terri-
torial adjustment. In a community where feeding of bob-whites
in farmyards or about buildings is general, it is highly probable
that most coveys are first led in by old birds which have had
previous experience-mere boldness on the part of the leading
birds does not alone explain the evident familiarity with the
grounds often displayed.

Season
1932-33
1933-34
1934-35
Season
TABLE 68. TERRITORY NO. 67
First count
22 on Dec. 7
15 on Nov. 19
28 on Nov. 17
1932-33
1933-34
1934-35
M
18 on Feb. 11
36 on Nov. 21
10 on Nov. 17
OTTUMWA, IOWA.
Final count
Territory number 67 (table 68) was a barnyard territory
near Ottumwa, Iowa. It was deliberately strengthened in 1932
by the planting of a cane food patch nearby. The 22 birds
present in 1932-33, with no recorded change until mid-February
or later, probably represents very nearly carrying capacity. In
1933-34, the territory seemed under-populated at first but was
situated in an area generally over-populated; the subsequent
influx, then, was not unexpected and by February had filled
up the territory to about the same as the year before at this
tinne. Chinch bugs and drouth ruined the food patch for the
season of 1934-35.
17 on Mar. 22
22 on Feb. 19
17 on Jan. 27 |
Territories number 67 and 68 (table 69) were part of a
game demonstration area established on private farmland by
the Iowa Fish and Game Commission. Most of the quail counts
for 1932-33 were made by deputy wardens and were taken from
the office files of the Commission.
TABLE 69. TERRITORY NO. 68
First count
Cause of difference
Egress or mortality
after Feb. 11
Influx probably from
No. 68
Starvation and predation
OTTUMWA, IOWA.
Final count
14 on Mar. 22
24 on Feb. 19
0 by Dec. 8
Cause of difference
Unknown; data
incomplete
Egress and predation
Starvation
It is very probable that much of the 1933-34 egress from
to ritory number 68 (table 69) resulted from birds moving into
the adjacent farmyard territory number 67.

360
E
The history of territory number 68 is extremely significant,
as it furnishes a concrete example of how environmental carry-
ing capacity for winter bob-whites may be raised-a very differ-
ent thing from simply increasing the security of populations
already within the carrying capacity of the land. By the plant-
ing of a patch of cane in an opening in a large woodlot, an
entirely new habitable territory was created. This place form-
erly had not been regularly occupied, and it was at a sufficient
distance from neighboring occupied territories as not to dle-
tract appreciably from their carrying capacities.
While inadequate records were kept for the first season
(1932-33) of the food planting and while the drouth ruined it
for 1934-35, the data for 1933-34 indicate that more birds were
thereby accommodated than had been possible before. Although
the improvised territory was doubtless over-populated early in
the season, the 24 birds wintering there were 24 that probably
would not have survived otherwise. It is true that we cannot
be too sure of what might have happened had there been no
food patch in 1933-34, but we have contemporaneous data on
surrounding populations which lost heavily because of over-
crowding as matters were.
The birds filling up the new territory, number 68, in the fall
of 1933 were very likely some that spent a great deal of their
time ranging in the woods. We have found that the vast
majority of so-called "wood coveys" on our Wisconsin and
Iowa observational areas were only partially woods-dv elling,
and were at least partially dependent upon cultivated grains or
seeds of certain field weeds for food. Granted that the quail of
territory number 68, deprived of the cane, might have picked
up a comfortable living on squirrel-opened acorns for a sub-
stantial part of the season, it is not improbable that sooner or
later they would have had to go elsewhere. The availability of
the food patch could hardly have had any effect other than to
relieve the congestion in neighboring territories, with a conse-
quent lessening of wintering mortality.
SURVIVAL DATA FROM LARGE AREAS
It has been shown that a territory may exhibit a greater
definiteness of winter carrying capacity when considered
with adjacent territories collectively rather than when considl-
ered individually. This is especially true in areas where inter-
change of birds between coveys takes place more or less con-
stantly throughout the winter. Carrying capacity under these
conditions does not appear to be so much a property of a
specific territory as it is a property of a collective land unit
embracing a number of adjacent or neighboring territories...
For example, the collective unit composed of the adjacent
361
territories number 4, number 17, number 18 and number 19
(table 22) has shown a uniformity of carrying capacity not
evident in any constituent territory by itself. Similarly, those
of the Class Four territories upon which there have been vary-
ing survivals have been territories situated at the borders of
observational areas, adjacent to territories not under observa-
tion and with which they may have formed territorial combina-
tions of more definite carrying capacity. This is rendered more
likely by the fact that practically all of the data which may be
judged contradictory to the concept of year to year definiteness
of winter carrying capacity are those that are under the great-
est suspicion of being incomplete.
On the same basis may be explained the indefiniteness of
carrying capacity shown by the problematical area "A" in the
original presentation of data for consecutive seasons [Erring-
ton (26), table at the bottom of page 113 misplaced in printing
from between fourth and fifth lines at the top of page 114].
Split up for more thorough analysis, the published data from
area "A" are derived from territory number 2, which is a
distinct aggregate of known covey ranges, and from territory
number 45, which adjoined quail-occupied and uncensused
agricultural land and hence had an indistinct identity as a
territory. The reliable data from number 2 show uniformity
of carrying capacity; the questionable data from number 45
do not.
Obviously, the larger the environmental unit under close
observation, or the more isolated it is from neighboring units,
the less will be the likelihood of error being introduced by
unknown happenings in borderline territories. Obviously, also,
the larger the unit the greater will be the likelihood of the unit
containing complete rather than incomplete territories and
incomplete combinations of territories.
The most significant data of this sort in existence come
from Prairie du Sac, Wis., where an area of 5 square miles
has been kept under observation for six consecutive winters.
The data from this area have been published in some detail for
the six seasons [Errington (20), (23), (32); Errington and
Hamerstrom (35)].
Taken collectively, the Prairie du Sac survival data for the
winters of 1929-30 and 1930-31 indicate that the wintering popu-
lations had not yet recovered sufficiently from the starvation
losses of 1928-29 to exceed the carrying capacity of the land.
The loss from predation of 5.8 percent per 90 days of the 1929-30
population of 121 birds and the 5.4 percent predation rate for
the 257 birds of 1930-31 signify a substantial security under
ordinary conditions for the populations wintering at these
levels.
The first inkling of the precise carrying capacity of the 5
362
of
square miles at Prairie du Sac was gained at the conclusion of
the 1931-32 season. A 400-bird population suffered a predation
rate of 12.5 percent per 90 days, enough to reduce the wintering
population to the vicinity of 329 birds by spring. Actually, a
starvation loss of about 39 birds occurred, but the starvation
represented an emergency so late in the winter that, for
purposes of calculating survival levels for the best of conditions,
it may be neglected. It is plain that, except for the emergency,
practically all of the 39 starved birds would have survived-
hence, carrying capacity for 1931-32 was virtually demon-
strated at 329 birds.
For 1932-33, a season attended by no severe starvation or
other emergencies, the survival was about 339 of an initial 406
birds, the predation rate of 12.7 percent per 90 days being
similar to that of 12.5 percent for the similar population of
1931-32.
į
The winter carrying capacity for the area for the first 4
years of field study, then, apparently fluctuated slightly
around 330 birds.
The carrying capacity of the area was doubtless lowered by
the wholesale debrushing of roadsides carried on in December,
1933, by CWA relief labor. The habitability of a number of
covey territories was not only impaired but in some cases virtu-
ally destroyed, and the coveys were evicted or rendered vulner-
able to depredations of natural enemies.
By spring of the 1933-34 season, the surviving population
was but 288 of an initial 433, the predation rate having been
accelerated to 24.4 percent per 90 days. The 288 survival
probably is not far from the carrying capacity of the area as it
now exists, since the December roadside debrushing seemed to
evict the equivalent of about two coveys.
The season of 1934-35 was attended by pronounced emer-
gency conditions [Errington (32)], and the resulting data must
be examined very critically if they are to be given any signifi-
cance from the standpoint of carrying capacity. Prior to the be-
ginning of the fall studies, the quail in this part of Wisconsin
had been subjected to a short shooting season, but so few birds
were known to have been bagged in the area that the net effect
of the shooting was in all likelihood negligible. Food shortage
and severe weather constituted the complicating factors.
S
Out of an initial late fall and early winter population
established at 411 birds, only 196 were still on the area by
spring. Of the 215-bird decrease, a total of 39 apparently moved
out of the area; the balance of 176 were evidently lost, and, in
addition, 8 birds that appeared to come into territory number
39 from the outside. Of the 176-bird decrease, representing
mortality of the initial population, the loss of about 20 was
attributed on fair evidence to starvation following an ice storm
in January and 40 more to a blizzard which struck at the end of
4
363
February and left severe losses behind it, notably in territories
number 5 and number 38.
The loss from predation on the Prairie du Sac area for
1934-35 was approximately 100 birds over an average observa-
tional period of 107 days, or at a rate of 20.5 percent per 90 days.
The preponderance of the predation losses occurred in terri-
tories associated with number 6 (including number 12, number
15, number 16, number 54) and in territories number 4, number
13, number 14 and number 29, all of which were heavily over-
populated, either at the beginning of the season or by reason of
the forced influx of birds driven from territories number 19,
mumber 20 and number 39 by winter food crises.
Study of the data, from those territories or groups of terri-
tories mainly occupied during 1934-35, shows that, except for
the starvation variable, the territories accommodated, with
security from predators, just about the population levels one
might have expected from their past history. The winter
Survivals for 1934-35 of the regularly occupied territory groups
in Classes One to Three may be compared with their average
demonstrated median survivals of the preceding years (table
70):

Territory
number
No. 1
No. 5 and
No. 13
No s. 6, 12, 15,
16 and 54
No. 14
No s. 4, 17, 18,
and 19
No. 20
No. 29
92
1st Count Final count
1934-35
1934-35
11
16
72
17
91
18
27
TABLE 70
54
50
0
59
0
16
Median car.
cap. 1929-34
17
105*
53
lethal
59
21
17**
Chief cause of
1934-35 losses
Interchange
Egress and starvation;
predation in No. 13
Predation
Egress and unknown
Predation and egress
| Egress; food crisis
Probably predation
* For the three years during which the territories were most nearly filled.
Estimated carrying capacity.
A comparison of columns three and four in table 70 proves
that the 1934-35 survivals for territories in which predation
was the principal cause of loss checked closely with the carry-
ing capacities as previously determined. This is notably signifi-
cant in view of the population shifting and massing precipitated
by the emergency conditions.
Territory number 1 (see tabular data and pertinent dis-
cussions) suffered no detected loss from predation for the
apparent reason that the dispersal of the drifting birds about
as fast as they came in (from number 5 and number 39 in par-
ticular) rarely permitted top-heavy concentrations to endure
for a dangerous length of time. The lethal record of number
12 for 1934-35 was probably due to the over-populated condi-
6. In cases where there was no true median the observed count closest to the median
was used.

364
tion of the territories associated with number 6 to which it was
adjacent and of which, in actuality, it comprised a part. Road-
side debrushing during 1933-34 apparently wrecked what
carrying capacity number 13 ever had in the first place. Terri-
tory number 14 was the well known lethal and was not expected
to winter any birds. The drop of four birds for territory num-
ber 15 does not represent mortality or any lowering of carrying
capacity; so far as we could see the birds simply made a late
winter shift to a neighboring territory.
The larger territory groups such as number 6 and associated
territories of number 13, number 15, number 16 and number $4
(table 7) and the number 4, number 17, number 18, number 19
group (table 22) revealed again an essential definiteness of
carrying capacity corresponding to the median obtained from
the annual survival figures.
BANDING RESULTS COMPARED WITH OBSERVATIONAL
CENSUS DATA
It was made a general policy not to do much banding r
collecting on the areas where populations were to be observed
under conditions as natural as possible. Banding, itself, is not
considered a very disturbing factor, but the necessary winter
baiting of the traps plainly influences covey routine to some
extent. For this reason, banding operations were largely e-
stricted to an area near Madison, Wis., where the usual type
of survival studies so far described were not carried on at the
time.
We have for this area substantial data for three consecutiv
seasons: Observational data for the first, and banding data for
the last two. The observational data were obtained by Erring-
ton during the winter of 1929-30. The banding data are on file
in the office of Prof. George Wagner of the University of
Wisconsin and represent the work of a number of cooperators,
particularly H. G. Anderson, from 1930 to 1932 [Errington
(18)].
Trapping and banding have the great advantage of proving
beyond question what individual birds an investigator may be
dealing with. Their chief drawback has to do with the virtuaal
impossibility of catching all of the birds in an area at times
when that is most desired. While most bob-whites may be
easily trapped for the first time under favorable conditions, an
while many individuals become habitual "repeaters," som
birds become decidedly "trap-wise" after the fright of having
been caught and handled once and only with difficulty ar
caught thereafter.
We feel, however, that the intensive winter banding record s
to which we have access give a nearly accurate total of the num
ber of birds frequenting this one area for the seasons indicated
365
and that they demonstrate certain covey movements, but that,
so far as survival data are concerned, they are inferior to our
notes from field observations. It is plainly easier to locate and
secure a count on an ordinary covey of birds than to get that
covey into a trap, particularly if it is not pressed for food.
TABLE 71. TERRITORY NO. 69
Season
1929-30
1930-31
1931-32
UNIVERSITY MARSH farm,
MADISON, WIS.
First count
Final count
40 on Nov. 20
57 on Mar. 2
57 banded birds recorded during winter
47 banded birds recorded during winter
Influx of a border covey of 19 about Jan. 15 was responsible
for the 1929-30 population rise for territory number 69 (table
71).
Season
1929-30
1930-31 1
1931-32
TABLE 72. TERRITORY NO. 70 - UNIVERSITY MARSH FARM,
MADISON, WIS.
Cause of difference
Influx
First count
Final count
43 on Nov. 20
38 on Mar. 2
37 banded birds recorded during winter
54 banded birds recorded during winter
Cause of difference
Mainly predation

There was an apparent shifting of population from territory
number 69 (table 71) to the adjacent number 70 (table 72) early
in the season of 1931-32. This was presumably due to human
activities in connection with extensive building operations in
what had formerly been regularly occupied quail range. That
the driving out of the birds in this case did not necessarily con-
stitute lethal eviction is indicated by the data from the two
adjacent territories combined (table 73):

Season
First count
Final count
1929-30
95 on Mar. 2
83 on Nov. 20 1
94 banded birds recorded during winter
1931-32 | 101 banded birds recorded during winter
1930-31
TABLE 73. TERRITORIES NO. 69 AND NO. 70 COMBINED.
Cause of difference
Influx and predation
Some slight allowance should be made for the possibility of
birds escaping the banding traps on territories number 69 and
number 70, but the totals recorded for 1930-31 and 1931-32 are
robably not far from the total numbers of resident birds. No
wintering losses were noted during the season of 1930-31, but a
oss of at least two was known to have occurred in 1931-32. All
in all, it seems as if the survivals for the one observational and
the two banding seasons on the adjacent territories match up in
the vicinity of 95 birds (table 73). Ninety-five birds, then, we
would say is very close to the winter carrying capacity of the
qombined territories or the carrying capacity of this area as a
whole as it has existed for the period of our studies.
366
PART III. ANALYSIS OF CARRYING CAPACITY
UNIFORMITY OF WINTER CARRYING CAPACITY
Stoddard (70 p. 171) has already pointed out that a covey
of
quail may occupy a favored area of ground year after year with
little or no increase in numbers. He goes on further to state:
"Evidence [from banding data] is at hand to show that
every member of a covey in one of these favored ranges may
wander away during the nesting season; that the covey occupy-
ing the range the following winter is made up of birds of neigh-
boring coveys and their offspring; and that at best, a very few
birds of any covey occupy the same range from year to year.
997
The more limited banding data from Wisconsin [Errington
(18)] confirm those of Stoddard and support the conclusion
that ". . . the redistribution of the adult quail population
after the breeding season, within limits of a half or three-quar-
ters mile or even greater radius, may be to no small degree
fortuituous; a bird spending the entire winter within a quarter-
mile or less of the center of the covey territory may the next
season winter in a territory possibly a couple of miles away. In
other words an individual bob-white may continue to live in
approximately the same place from year to year, or it may

not."
It should then be plain that the occupancy of a given terri-
tory by the same apparent number of birds for a succession of
seasons by no means proves that the territory is occupied by
the same birds one season after another. Why a given territory
should hold a maximum of only about so many birds is not so
plain.
Stoddard (70 p. 170) says that by repeated combinations the
coveys tend to keep their organization of normal size. We
in our northern studies have found this to be one of the factors
operative. But what determines this "normal size"? Why is
10 to 12 normal for the covey that occupies a given territory;
why is some other number normal for still another territory?
We admit that we do not know the answer, nor can
Wre
advance what seems to us a reasonable hypothesis. We can,
however, submit what data we have for critical examination, if
only to permit clearer definition of the problems.

Winter carrying capacity roughly approximates the number
of birds sufficiently well situated in their environment to be
secure from enemies and to be adjusted with respect to intra-
specific relations. If a population of sound individuals suffers
severely from predation or if concentrations past a certain point
are consistently reduced by the splitting off and departure of
7. We recommend the careful reading of Stoddard's excellent chapter on movie-
ments of bob-whites, pp. 167-182, for those who may be particularly interested in this
phase of the subject.
367
•
birds, the evidence indicates a condition of overcrowding and
insecurity, though the birds may be both strong and well-fed.
Since reductions of over-populations to the comparatively
secure winter equilibrium at the level of environmental carry-
ing capacity are accomplished chiefly by predation and by
egress, any sort of reliable determination of carrying capacity
necessitates separate consideration of the losses due to preda-
tion and egress and the losses due to something else. This
necessitates correcting the actual survival figures, to eliminate
so far as possible the confusion caused by losses as from late
winter starvation and other irregular or atypical emergencies.
Allowances have to be made also for seasons during which
wintering territories were under-populated and occasionally
for seasons unproductive of scientifically acceptable data.

The median survival figures for the individual territories or
groups of territories probably give as close an approximation
of the season to season carrying capacity as we are likely to ob-
tain (table 74). Corrections in survival figures have been made,
as indicated, on the basis of information previously given in the
text in the discussions relating to the particular territories. All
territories in the reliable Classes One to Three are eligible for
consideration, in combination if not singly.
Table 74, presenting the survival figures for Classes One to
Three in corrected form, provides what we consider an accurate
picture of what would have been the full wintering survival on
the various territories under non-emergency conditions. Under
those conditions, the reduction of over-population is brought
about simply by the failure of the environment to accommodate
more than a certain number, season after season. The "median"
of table 74 expresses approximately these accommodation
limits. Populations in excess of this number seemingly are
redduced through their vulnerability to predation or are forced
by overcrowding into inferior environment elsewhere. In the
latter event, excess populations are reduced anyway, usually
through their vulnerability to predation in their new but
ir adequate range.
SEASONAL REDUCTION OF BOB-WHITE POPULATION
SURPLUSES
If allowance is made for the variables introduced by star-
vation emergencies, atypical situations, territories under-popu -
lanted or vacated voluntarily rather than through necessity, or
any other cause except predation or egress forced by vulnera-
bility to predation, it is to be seen that the preponderance of data
8. A state of under-population of a territory group is apparent when the population
winters with security from predation but at a decidedly lower level than the level
usually accommodated. Under-populations are, of course, most likely to occur in the
wake of wholesale losses from starvation, over-shooting, drouth, etc.

368
!
from the superior Classes One to Three (territories number 1 to
number 34) either support the concept of definiteness of carry-
ing capacity or do not refute it. Neither may the concept de
said to be refuted by the relatively inferior data of territories
number 35 to number 70; indeed, from these it derives no small
support, even from those data which superficially may appear
contradictory.
All in all, what we are trying to get at in our attempts to
analyze carrying capacity is: What is the population of adult
bob-whites that a given habitat, as it usually exists from year
TABLE 74. MEDIAN SURVIVAL OR APPROXIMATE SEASON TO SEASON
WINTER CARRYING CAPACITY.

Territory and
median (on basis
of corrected
survival)
Territory No. 1
Median: 17
Territory No. 2
Median: 33
Territory No. 3
(In combination
with No. 37)
Median: 76*
Territories
No. 4, No. 17,
No. 18, and No.
19 Combined
Median: 59
Territories
No. 5 and No. 13
Combined
Median: 105**
Territories
No. 6, No. 12,
No. 15, No. 16,
and No. 54
Combined
Median: 53
Territory No. 7
Median: 48 (?)
Territory No. 8
Median: 20 (?)
Season
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
1929-30
1930-31
1931-32
1932-33
1929-30
1930-31
23
35
32
32
29
31
33
33
Territory under-populated
about 77 1 about 77
about 76 | about 76
Population evicted by man
1929-30 | Territory under-populated
1930-31
60
1931-32
64
1932-33
59
1931-32
1932-33
1933-34
1934-35
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
1932-33
1933-34
1934-35
1932-33
1933-34
1934-35
Actual
survival
1
17
17
17
17
Territory under-populated
17
17
18
18
16
16
51
59
Corrected
survival
46
53
66
50
Territory under-populated
Territory under-populated
Territory under-populated
111
105
51
38
0
60
64
59
20
21 (?) |
7
56
59
54
96
Territory under-populated
62
58
111
105
52
53
66
50
51
38
48
1
Reason for
correction
Late starvation of 12
Loss from cold of 2
Loss of 5 probably due
to eviction by man
Starvation and egres s
of about 42
Later loss of 4
Loss of 6 from
shooting, etc.
| Eviction
20
21 (?)
20 (?) | Atypical
369
Territory No. 9
Median: 20
Territory No. 10
Median: 54
Territory No. 11
Median: 30
Territory No. 12]
Territory No. 13
Territory No. 14 |
Territories
No. 15 and No. 16)
Territories
No. 17 to No. 19
Territory No. 20
Meedian: 21
Teritory No. 21
Median: 5
Territory No. 22
Mec lian: 15
Territory No. 23 |
Territories
No. 24 to No. 28
Teritory No. 29
Me dian: 16
Territory No. 30
Median: 16
Teritory No. 31
Median: 16
Territory No. 32
Median: 20
Territory No. 33
Median: 11
Territories
No. 34 and No. 61
Median: 18
1932-33
1933-34
1934-35
1932-33
1933-34
1934-35
1929-30
1930-31
1931-32
1932-34
1929-35
1929-35
1929-35
1929-35
1929-35
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
1932-33
1933-34
1934-35
1933-34
1934-35
1932-35
1932-35
1929-30
1930-31
1931-32
1932-33
1933-34
1934-35
1929-30
1930-31
1931-32
1929-30
1930-31
1931-32
1929-30
1930-31
1931-32
1929-30
1930-31
1931-32
1929-30
1930-31
1931-32
I
I
20
20
24
55
54
Territory under-populated
30
30
Territory under-populated
32 1 32 !
Territory vacant or under-populated
(See territory No. 6 group)
(See territory No. 5 group)
Territory consistently lethal
(See territory No. 6 group)
(See territory No. 4 group)
Territory under-populated
Territory under-populated
21
22
21
22
Territory irregularly occupied
0
5
5
15
0
19
0
20
20
24
I
11
11
12
18
21
10
55
54

18
5
5
4
17
15
Territory of no demonstrated habitability
5
16
Territory under-populated
16
16
12
17
Territory under-populated
13
16
17
15
Data inadequate for conclusions
Territory under-populated
13
14
12
18
17
17
Territory under-populated
16
16
20
20
20
1
11 (?)***
11
12
Eviction
18
21
18
Late winter influx
Bird collected
Late starvation of 6
Late starvation of 11
Late starvation of 5
Late storm loss of 3
Late starvation of 20
Bird collected
Late winter egress
| Late starvation of 8
* Mixed bob-whites and ring-necked pheasants [Errington (26) j.
**
Carrying capacity probably lowered for 1934-35 by the debrushing of a part of
territory No. 13 the season before.
*** This figure may not have too much significance because of the late winter starva-
tion mortality recorded in this territory for the 1929-30 season.

!
1
370
to year, can winter under optimum climatic conditions and what
are the basic factors limiting the number that may be accommo-
dated? The number that may be accommodated, as we have
indicated, appears to be remarkably definite and represents the
density which natural enemies are not able to reduce materially
in the course of the winter. In other words, whatever else it
may be, it represents the population which is intrinsically
secure in its winter environment, both from simple predation
and from eviction by predators.
1
A review of the survival data shows that the population
densities surviving winter predation are far more uniform for
specific territories or territory groups than are the densities
which may be present at the beginning of the winter. The
beginning densities are likely to be highly variable, though
usually above rather than below the carrying capacity of the
environment. In the vast majority of the many instances in
which the initial recorded populations were below or up to
(but not above) carrying capacity, slight further losses from
predation alone were suffered. In most of these instances, the
occurrence of densities at the level of carrying capacity as ealy
as December or even November meant that the resident birds
had already suffered about as much predation mortality as they
were going to for the season.
We have listed 119 specific instances in which it was clear
that territories had or should have (barring late starvation
emergencies, etc.) wintered populations up to their carrying
capacity. In 69 instances the territories had been almost.
exactly filled at the start of the season's observations; in 43, the
territories had been distinctly over-populated at the beginning;
in 7, distinctly under-populated, to be filled during the winter.
The instances relating to initial over-populations are, to our
way of thinking, the most significant. They demonstrate with
inexorable clarity the instability of populations that exceed the
capacity of the land to accommodate. Again and again, excess
populations have been reduced by spring to the level of carry-
ing capacity-whatever that may be for the specific territory
or the aggregate of territories under observation.
Aside from losses of immature birds during the growing
season, the strongest annual acceleration of predation upon
bob-white seems to come in late autumn, when the habitability
of large tracts of land is lowered by the falling of leaves from
deciduous brush and by the drying up of much herbaceous
plant growth. The reduction of cover is accentuated by the
early snows, and evidences of predation may for a time be
very conspicuous. Then, sooner or later, the surplus birds
from the season's breeding are killed or leave; and the remain-
ing population enjoys a comparative security from orolina y
simple predation until spring and presumably until there is
again a surplus.
371
That the severity of fall and winter predation upon healthy
adult birds is largely dependent upon the degree to which the
environment is over-populated is indicated by experimental as
well as by observational evidence. The artificial removal by
shooting of surplus birds on Iowa game management areas in
November, 1933, resulted in an apparent increase in security
for the wintering populations. The populations on 10 shot areas
collectively lost during the winter at the rate of 10.8 percent
and those on the 4 unshot areas studied as checks lost at the
rage of 28.3 percent [Errington and Hamerstrom (35)].
Our censuses of the shot populations in particular were
beset by imperfections, yet the difference in winter loss rates
on the shot and unshot areas surely points to some relief of the
normally over-populated fall condition as a result of the shoot-
ing. This is precisely what one might expect theoretically,
although the effects of shooting and of natural predation upon
an over-population differ in significant respects.
Predation is infinitely more selective of vulnerably situated
birds than shooting, for the obvious reason that man, by means
of trained dogs and modern firearms alone, is capable of taking
toll from bob-white populations that may be virtually secure
from natural enemies. Moreover, natural enemies prey largely
according to the comparative ease with which a prey species
may be caught, and they tend to neglect species that no longer
provide them profitable hunting; whereas man may prize a
hunted species more because of its rarity and pursue it the more
eagerly.
1
In nature the evidently increased security of normal winter
bob-white populations, after they have been trimmed down by
predation to fit the carrying capacities of the areas studied,
indicates that the actual vulnerable surplus has been removed.
In shooting for sport it is highly probable, even if the exact
number corresponding to the seasonal surplus were taken, that
pressure would be applied unevenly upon coveys both over-
populating and under-populating their coverts. The shooting
of an insufficient number of birds from an over-populated terri-
tory would still leave an over-population vulnerable to preda-
tion. The shooting of birds from territories capable of winter-
ing the populations they have might leave some environment
under-populated for the season, especially if the population as a
whole has settled down to a rather circumscribed winter rou-
tine. This is probably as reasonable an explanation as any for
the relatively high winter loss of 10.8 percent suffered by the
populations on the experimentally shot areas, compared with
the losses of secure unshot populations, which losses, as
measured, commonly have not exceeded 6 percent.
Midwinter adjustments of bob-white populations between
territories also reveal a close relationship between over-popula-

372
tion and vulnerability to predation. The splitting and recom-
bining of coveys in a densely populated group of territories
may be looked upon, at least in part, as a manifestation of
uneasiness resulting from the possibility of too many birds
occupying the same environment at the same time.
If more birds join a wintering covey, which had approxi-
mately filled the occupied territory to carrying capacity before
the union, the covey (resident birds plus newcomers) may with
comparative promptness suffer losses tending to trim down he
over-population, that is, unless the over-population is relieved
by the departure of the joining birds or by an equivalent
number. The loss of the top-heavy surplus in most of the
known instances has occurred within the few weeks following
the influx. Sometimes tragedies of this sort have been repeated
two or three or even more times in a given territory during the
season and are particularly to be noted when remnants of
coveys depleted by starvation or evicted from territories else-
where attempt to find safer quarters.
If the territory entered happens to be strong and under-
populated (as is infrequently the case by mid-winter), the new-
comers may station themselves there with security. But if their
influx means anything more than a temporary over-population
for the territory and a compensatory egress is not made, some
birds are practically sure to suffer from it.
PREDATION AND CARRYING CAPACITY
Publication of the mere fact that predation has proved to be
a major medium in the reduction of bob-white over-populations
almost inevitably serves to focus public attention upon preda-
tors rather than upon what predation signifies. It is difficult in
the extreme for the public to recognize that, in this instance at
least, predation is but a symptom and not a cause of biological
unbalance.
The data which we have on bob-white losses and predator
populations [see especially Errington (26)] indicate that within
ordinary limits there is no evident relation between kinds and
numbers of predators and the severity of predation upon bob-
whites under natural winter conditions.
We do not say that exceptions to this generalization are not
possible, actually as well as theoretically. It is, of course, easy
to postulate that if there were no predators there could be no
predation, but such speculation is idle. It may be counter-
postulated with a great deal more biological basis that as long
as there is abundant edible life some life will exist to eat it,
though not necessarily the same species which we are in the
habit of referring to as predators. Familiarity with the
predaceous tendencies frequently displayed by large numbers
of birds and mammals which are not commonly thought of as
T
1
[
373
predators leads one to suspect that practically any form of life
may become predatory to some degree when the opportunity
or the necessity presents itself." Predation, then, depends more
upon the presence of something vulnerable as prey than upon
the systematic position or the predilections of the animals
which may do the preying.
It seems entirely reasonable to suppose that predation is a
normal phenomenon associated with life, reflecting the reaction
of hungry creatures to the food which happens to be most
available. If we consider parasitism and predation together we
may perhaps reasonably suppose also that the net pressure of
these combined may not change vastly except as the vulnera-
bilty or the susceptibility of organisms to them changes.
Over-populations generally are conspicuous targets for
attacks by predators or parasites. Nature may abhor a vacuum,
but she abhors over-population not a great deal less. Someone
has said that Nature has more than one arrow for her bow.
Over-populations are insecure because they are over-popula-
tions. If they are not reduced by one thing they are by another.
In the case of the bob-white, the winter over-populations.
which we have studied have been reduced mainly by predation,
but it by no means follows that they would not have been reduc-
ed had it not been for predators, or that reduction in numbers of
the predators would have made the over-populations any more.
secure. The evidence is all to the contrary.
Territory number 14 furnishes one of the best cases in point.
The predator population of this territory, in the course of the
six winters during which it has been under observation, chang-
ed greatly in composition, both with respect to numbers and
to species of predators present; yet the patently lethal character
of the environment for wintering quail has not changed per-
ceptibly. Fluctuations in numbers and species of predators have
been apparent from one winter to another on practically all of
the areas under regular observation [for examples, see Erring-
ton (26)], but the bob-white survival data have not shown any
connection with these fluctuations.

Most of the season to season differences in predator popu-
lations on the observational areas have been due to natural
causes, such as inter- and intra-specific relationships of the
predators, losses among resident predators as from disease
[Errington (16) and unpublished; Green and Shillinger (39)]
an accident, irregularities of residence of migratory forms, etc.,
plus the usual sporadic shooting and trapping by the public. On
a few of the areas, predators were deliberately encouraged; and
a few others, they were drastically campaigned against
*

9. Examples of primarily vegetarian groups which upon occasion may be conspicu-
ously predaceous include gallinaceous birds (notably turkeys, pheasants, domestic
chickens) and nearly all rodents.

374
Fo
[Errington and Hamerstrom (35)]. But whether the winter
predators were encouraged, left comparatively unmolested, or
actively persecuted, whether the predators were few or many,
any effects that the resulting differences in predator popula-
tions may have had on winter survival data have been so slight
as to be unmeasurable. This is well brought out by table 74 and
by practically all of our survival figures for specific areas oyer
considerable periods of time.
COMPENSATORY PRESSURE OF PREDATION ON
BOB-WHITE POPULATION SURPLUS
Great horned owls (Bubo virginianus) and Cooper's hawks
(Accipiter cooperi) are two of the most formidable of quail
enemies and the ones to which most of the known winter pre la-
tion has been traced. On our observational areas, horned owls
have probably killed more winter bob-whites than all of the
other predators combined; Cooper's hawks and marsh hawks
(Circus hudsonius) ranked a weak second and third¹º and ed
and grey foxes (Vulpes fulva and Urocyon cinereoargenteus)
a still weaker fourth, at least so far as concerns detected
mortality. All of the many other species of predators studied,
including the house cat (Felis domestica, of alien origin and
bird-killing repute) have trailed far behind as known predators
upon winter bob-whites.

Contrary to what would seem most reasonable at first
glance, lower populations of the most formidable predatory
types, down to scarcity or actual absence on the observational
areas, has not resulted in any appreciable lessening of the net
pressure of predation upon bob-white winter populations. The
1931-32 season showed terrific horned owl predation upon the
occupants of the lethal territory number 14; in 1932-33, the
horned owls were gone but the losses continued, this time
through the medium of grey foxes; in 1933-34, the foxes were
greatly reduced in numbers, but still the bob-white losses were
annihilatory because of foxes and general predation. In other
instances, predator populations have noticably increased,
sometimes to top-heavy peaks, without any apparent effect on
bob-white survival as compared with other winters. Not one
have we been able to establish a clear-cut case of differences in
predator kinds and numbers having any net influence upon the
losses from predation suffered by wintering bob-whites.
The one thing that seems really to count in determining the
severity of the predation is the position of the quail population
with respect to the carrying capacity of the land. This severity
we have found to be quite predictable on areas having carrying

10. Stoddard, however, has found the Cooper's hawk to be the supreme predatory
quail enemy in the South, and the marsh hawk to be of negligible consequence. Both
hawk species were abundant on his observational areas, though horned owls were
fairly common and foxes uncommon.

375
capacities demonstrated by recorded survivals over a period
of years, apart from complications brought on by starvation
emergencies, destruction of habitats by wholesale debrushing,
burning, fall plowing, heavy pasturing and the like.
Seemingly irrespective of the kinds and numbers of preda-
tor's present, the severity of simple winter predation will depend
upon how many quail there are beyond the carrying capacity of
the land. For example, in table 74 the median of 17 may be
taken as the carrying capacity for territory number 1; birds in
excess of this approximate number will either have to leave or
be killed. Even for the grouped territories number 6, number
12 number 15, number 16 and number 54, which show collective
fu survivals of such widely separated extremes as 50 and 66,
th median of 53 is not far from the number of birds of a fall
po ulation which can be expected to survive any non-emer-
gecy winter.
If the wintering population is below the carrying capacity
of The land, or just within it, light losses from simple predation
may be predicted, in most cases not to exceed the rate of 6
percent per 90 days. Populations up to carrying capacity do
not seem to suffer at proportionately higher loss rates than
populations only partially filling the suitable winter environ-
ment available; at least, this appears true for well accommo-
dated populations as high as a bird per four acres, which is the
highest level that we have been able to census with required
accuracy.
We have been gaining a general impression, as yet unsub-
stantiated by adequate data, that securely situated Iowa bob-
white populations suffer from predation at a slightly higher
rate than corresponding Wisconsin densities in environments
of corresponding carrying capacities. It may be that predation
losses between 10 and 15 percent per 90 days for substantial
populations within the median carrying capacity of the land
may not be so exceptional. Our Iowa data are as a whole far
less trustworthy than the data from Wisconsin, if only for the
reason that at their best they cover but a 3-year period. Then,
too, we cannot be too sure that the annual environmental
changes due to central Iowa agricultural practices on larger
land units may not bring about decided changes in carrying
capacity from year to year. If central Iowa carrying capacity
for quail does change decidedly from year to year, at best,
survival for a given winter might fluctuate considerably from
the median derived from data from consecutive seasons, in
contrast with the greater uniformity of survival shown by pop-
ulations on the more stable Wisconsin ranges.

"
For the present, however, we may feel fairly safe in predict-
ing predation losses usually below 6 percent per 90 days for
secure winter populations. A hypothetical area of 4,000 acres
having a carrying capacity of a bird per four acres or 1,000

376
birds, would then lose from winter predation in the vicinity of
6 birds or less per 90 days of every 100 birds below 1,000. [If
the population on the given area exceeded carrying capacity,
the loss would amount to the excess, or approximately 200 (of
a population of 1200; 500 of a population of 1500; 1000 of a
population of 2000, etc.
Roughly, the birds over the thousand level in the above
hypothetical area represent the surplus population for the area,
and as a surplus they either have to move out or are doomed to
be killed during the winter. A bob-white population does not
have to be of high density to have a surplus; it only has to
exceed the accommodating capacity of the environment, pe
that high or low. A population of no more than a bird
square mile may have a surplus, if the carrying capacity of e-
land is less.
er
Under ordinary conditions in Wisconsin and Iowa, he
vulnerably situated surplus has been found to be reduced
largely through the medium of the more efficient types of quail
enemies, i. e., horned owls and the Cooper's hawks. When
these forms are absent or present only in low densities, the
reduction is apparently accomplished by enemies less adapted
to prey upon quail, such as marsh hawks and foxes. In the
absence of these, still less efficient quail enemies seem to exert
a compensatory pressure.
Red-tail hawks (Buteo borealis) and barred owls (Strix
varia) are species which, when competing with truly formidable
predator types for a vulnerable bob-white surplus, are hardly
to be classed as quail enemies. Nevertheless, these may on
occasion prey rather conspicuously on bob-whites, presumally
with enough force to reduce over-populations down to the usual
level of secure accommodation. Clumsy dogs, weak owls,
typically non-predaceous forms such as the ring-necked
pheasant [Leopold (46) p. 56] and rat to squirrel-sized rodents,
have all been known to kill adult quail; and in the aggregate
these may conceivably be capable of considerable pressure on
a bob-white surplus long enough exposed.
For that matter, the bob-white itself is not entirely beyond
suspicion as a killer of, if not a predator upon, its own species
[Stoddard (70) p. 222], to say nothing of the biological com-
plications attendant upon over-crowding in restricted habitats.
More than one species, upon analysis, proves to be the final
check upon itself, in one way or another.
"BUFFER" POPULATIONS AND BOB-WHITE LOSSES FROM
WINTER PREDATION
It has long been accepted practically without question that
population densities of rodents and other "buffer" species have
a profound influence upon the predation rate suffered by bob-
377
whee. The predation rate upon bob-white has been thought to
decine with rising buffer populations, and to rise with declin-
ing buffer populations.
Higher buffer populations have also been thought to have
an indirect effect in increasing bob-white predation losses
through the attracting of more predators into a given area, a
Icical corollary to the popularly held assumption that bob-
white predation losses vary with the number of predators. It
has further been thought that the subsequent decline of a buffer
population which has built up a heavy density of predators is
followed by increased pressure of the predators upon the resi-
dent bob-white population.
We do not say that there is no truth in the commonly ac-
ce ed ideas expressed above. We do not say that they may not
bentirely correct as to the relationship of buffer and predator
polations to bob-white predation losses under some circum-
coces. Stoddard (letter, Aug. 27, 1935) ably defends the man-
ament practice of keeping down populations of cotton rats
(Sigmodon spp.) on south-eastern quail lands as a means of dis-
couraging predators which are incidentally egg eaters. He has
uniform data on over 2,000 quail nests, compared with which
our own data are altogether too limited and obscure to justify
making many positive statements on this phase of the subject.

But the data from our Iowa and Wisconsin observational
areas indicate that if there is any real balance between buffer
and predator populations and winter predation upon bob-
white, it is at least not a conspicuously delicate balance [Er-
rington (26)]. We have no evidence which would lead us to
suspect that fluctuations in buffer populations have played any
parft in either mitigating or increasing predator pressure on the
particular bob-white populations with which we have been
working.
Errington (15) published what he considered at the time to
be an example of a quail population rendered vulnerable to
horned owl pressure by reason of scarcity of rabbits and other
usual horned owl prey, but a more critical analysis of the data
suggests an over-population of quail for the territory (number
48 in this bulletin) instead of a significant under-population of
buffers. In the same paper, the Wingra Wild Life Refuge was
rs.ven as an example of an area having a quail population rela-
getely secure from horned owl pressure because of a teeming
abbit population; whereas, in the light of present interpreta-
ition of the evidence, the security of the quail was due simply to
the fact that they had not over-populated their environment
territory number 2, 1930-31).
While our methods of estimating buffer populations were
admittedly crude [Errington (26)] and not at all to be com
pared in precision with our quail winter census technique, it
į
378

was nevertheless possible to get some idea of major flutua-
tions in rodent and rabbit numbers. We knew beyond des-
tion that there was in south-central Wisconsin a top-havy
abundance of meadow mice (Microtus spp.) in the summer
of 1929 and the winter of 1929-30. We knew beyond question
that this peak collapsed and that for the next 2 years very few
meadow mice could be found in the observational areas. (on-
spicuous changes in the usual buffer fauna were to be noted in
a number of localities during the course of the studies, what-
ever may have been our inability to record these changes with
desired exactness.
But aside from any lack of relation between bob-white
losses from predation and fluctuations of buffer and preor
population densities as recognized or recorded, the apparent
year to year definiteness of environmental carrying capa ty
for wintering bob-whites is in itself the strongest evidence
against any close relation actually existing under ordinary on-
ditions. Even if we did not know that buffer and predator
populations had varied greatly in composition on the observa-
tional areas over a period of years, it would be asking a great
deal of coincidence to postulate, on the grounds of uniformity
of quail survival alone, that the population ratios of buffer and
predator species had themselves remained uniform for area
after area, year after year.

In connection with public or conversational discussions of
bob-white population vulnerability, we have frequently teen
asked the question: "What do the predators eat when they
can't catch the quail?"
When quail populations are too securely situated to be
preyed upon, the predators eat the rodents, rabbits and other
buffers or other over-populations which constitute the bulk of
their diet anyway. Quail should be regarded as an incidental
rather than as a staple food for predator populations under
normal north-central states winter conditions. If there are
surplus quail to be eaten, they seemingly will be eaten by some-
thing. If the wintering quail are securely situated, there is no
surplus, and, granted that the birds are in good condition and
ordinarily adaptive, they will suffer little loss. Whether there
is no quail surplus available to predators, or whether the birds
aren't there is of slight apparent consequence to the predato

In short, it is more than probable that predators could g
along very nicely if there were no bob-whites in existence,
there virtually are not in many localities within the geographic
range of the bob-white as well as the range of the various preda-
tory species. Bob-white populations at the maximum adult
level of a bird per acre [Stoddard (70), Leopold (46)] still
would not represent a chief source of food for predators gener-
ally, even if the entire quail populations were available. Act-
ually, early winter populations in much of the best of southern

379
Iowa quail country run between a bird per 2 and a bird per 6
acres, of which populations the vulnerable surplus rarely
exceeds 50 percent and seems more likely to average in the
vicinity of 30 percent [Errington and Hamerstrom (35)].
Commonly, the wintering densities are more nearly a bird per
12 or 15 or 20 acres, with a still lower vulnerable surplus, which
wuld mean rather slim picking for any considerable popula-
tion of predators at all dependent upon bob-whites for food.
Some of our analyses of horned owl pellets have shown
quail remains in as high a proportion as 15 percent of the pellets
examined (unpublished). This represents terrific pressure, of
an intensity sufficient to annihilate, in the course of a winter,
coveys occupying such lethal territories as number 14 in 1931-
32. It also represents the horned owl pressure applied to
populations which for some reason have far exceeded the
carrying capacities of their territories, as those of the number
6, number 12, number 15, number 16 and number 54 combina-
tion for 1934-35.
This incidence of quail remains in 15 percent of the owl
pellets of given collections should not be misinterpreted as
meaning that quail made up 15 percent of the diet of these owls
for the period indicated by their pellets. Seldom would a pellet
be composed entirely of quail remains, and in most cases
remains of other prey would predominate. Hence, it would be
more in keeping with accuracy to state that we have never
known the diet of even a quail enemy as singularly efficient and
as automatic in reaction as the great horned owl [Errington
(21)] to be made up of more than about 5 percent of quail by
bulk.
In our opinion, no other native predator can apply as much
pressure upon a winter bob-white over-population as the
horned owl. With bob-white constituting an observed maxi-
mum of not far from 5 percent by bulk of the horned owl's diet
under the most favorable conditions for predation which we
have been able to record, one may logically deduce that bob-
white populations as they ordinarily occur do not go far in pro-
viding a source of food for hungry flesh-eaters. Whether the
bob-whites may be plentiful, scarce, or absent, whether they
may be secure or insecure, predator populations usually are able
to subsist chiefly upon the rodents or rabbits or other so-called
affers which rarely fail to exceed by far the bob-whites in
ambers and surpass them by far in availability.
The evidence which we have does not lead us to believe that
Predator populations, under the north-central states conditions
which we have studied for the past 6 years, are likely to utilize
anywhere near the food supply available to them. We have
studied food habits of predatory species on a substantial scale
in connection with our regular researches as times when staple
prey species have been at high and at low levels.


380
It is quite apparent that the "Malthusian Principle" is not
the principal factor in determining animal populations in nature
[McAtee (60)], although it unquestionably is not without
application. Animals certainly have been known to starve,
especially under emergency conditions. There are clear in-
stances of top-heavy populations having been reduced by
starvation, but starvation does not appear to be the us tal
agency which holds most animal populations in check. So far
as the predator populations which we have studied are con-
cerned, the predators, with a few exceptions [see for example,
Errington (11)], had enough to eat at all times, whether prey
populations were comparatively low or comparatively high.
When the meadow mouse population of south-central Wis-
consin was at its peak in 1929, meadow mice were killed and
eaten in great quantities by a wide variety of animals, including
crows, bitterns and domestic chickens; yet all of this predation
made no perceptible impression upon the numbers of mice.
After the meadow mouse population had obviously fallen to a
level insignificant compared with what it had been, predators
were still eating and were apparently getting along perfectly
well on rabbits and deer mice (Peromyscus spp.) instead. Some
species, notably longeared owls (Asio wilsonianus), even con-
tinued to feed upon meadow mice in just about the same pro-.
portion as before [Errington (15)].
It seems, then, that a broad generalization may be made to
the effect that the usually staple prey populations are usuly
much more than adequate to support predator populations of
the kinds and densities that usually occur in the north-central
states. Bob-whites, being rarely if ever staple prey for any-
thing, may perhaps be regarded as but a side dish for hungry
flesh-eaters, entirely acceptable if conveniently available, easily
to be dispensed with if not.

FOOD AND CARRYING CAPACITY
Food is obviously one of the essential constituents of a
habitable winter quail territory. Its role in determining the
carrying capacity of quail environment should be carefully
discussed, as this subject lends itself especially to popular
misunderstanding.
It is true that the habitability of a wintering territory lis
closely correlated with the food supply, in the sense that the
must be enough high quality food available to hold and feed th
birds there. The amount necessary to sustain a wintering covey
is comparatively small, however, in terms of bulk; and carrying
capacity of bob-white environment does not vary directly with
the amount of food, save exceptionally. Only under some
emergency conditions or under those approximating the prim-
itive, have we found survival delimited by the amount of food
to be had during open winters.
381
The food situation for Iowa and Wisconsin quail seems
typically characterized by two extremes. Either there is not
enough food for any wintering population or there is a vast
abundance of food far surpassing the needs of any quail popu-
lation that could conceivably station itself in a circumscribed
area. In Michigan, Dalke (6) gathered grains and weed seeds.
from 1,377 random samples (each of 4 square feet) on three
sections of farm land on which he had been studying pheasants.
He computed from these samples that an average of 6,303
pounds of edible material was available per square mile for
fall and winter consumption by seed-eating animal life. That
a supply such as this would not be left unmolested for a single
species-quail or any other-stands to reason, but it would take
a great many quail eating between two and four ounces a week
to make much impression upon it.
Where there isn't enough winter food for any population, it
does not make a great deal of difference if a dozen birds or twice
as many try to exist there. If the food supply is ample and
regularly available to a quail population up to the demonstrated
carrying capacity of the land, increasing the supply still more
will not bring about a corresponding increase of carrying
capacity. If the ecological scales are set so fine that there is no
more than exactly enough for the wintering bob-white popula-
tion, they may be thrown out of balance at almost anytime, any-
way, as by the chance visitation of a numerous flock of sparrows
or other small birds.
Territories or potential territories usually critically deficient
in food are those on which, or near which, there is no cultivated
land, or on which the foods resulting from cultivation have.
been removed by clean cropping, burning, or pasturing, or have
been turned into the soil by fall plowing. Wild lands are partic-
ularly likely to be short of food, as well as lands reverted from
cultivation. Native food of high winter sustenance value for
bob-white may occasionally be very abundant according to the
season, but they may also be very scarce. These include
squirrel-opened acorns (Quercus spp.) certain of the Legumin-
osae, as tick trefoil (Desmodium grandiflorum) and hog peanut
(Amphicarpa monoica), and jewel weed (Impatiens spp.). An
exotic of similar irregular significance as quail food is the now
naturalized black locust (Robinia pseudoacacia).
A distinction should be made between the substantial types
of food which are essential to the quail as winter staples and
the succulent or fruit-like types which are valuable more for
their minerals, fruit acids, vitamins, etc., than for any energy-
supplying qualities [Errington (12); Leopold (48)]. Unless
a food is high in available protein, carbohydrate, or fat, it can-
not be expected to provide the nourishment required by quail in
cold weather. Quail starve in but a few days' time when com-
pelled, in confinement or in the wild, to rely too much for food
1
382
upon such common and readily eaten winter fruits as those of
sumac (Rhus spp.), wild grape (Vitis spp.), bittersweet
(Celastrus scandens) and Rose (Rosa spp.).
Man, through his settlement of the land has tremendously
increased the supply of available quail food over that to be
found under pre-settlement conditions, whatever may be the
other effects of his use of the land. As a by-product of settle-
ment, pigeon grass (Setaria spp.) and lesser ragweed (Am-
brosia artemesiifolia) are two weeds which contribute mate-
rially to making present bob-white populations possible. Man's
cultivated corn (Zea mays) we find to be the supremely im-
portant winter quail food for our Wisconsin and Iowa areas,
and soybeans and most small grains are important also.
Optimum conditions for Iowa quail seemed to exist about
1880. Since then, gradual intensification of farming practices.
has adversely affected quail environment from the standpoint
of food. Unwise land use has even impoverished and wasted
much of the food-productive top-soil itself. This granted, the
food situation for bob-whites on cultivated land is still uni-
formly superior to that for the birds on uncultivated lands.
Exceptions occur, of course, on wildlife refuges, etc., where
adequate artificial feeding compensates for the deterioration of
the food supply through plant succession and withdrawal from
cultivation.
Let it be granted also that a drouth such as the one of 1934
[see Errington (29)] may drastically cut down if not wipe out
the supply of quail food over wide areas, and that heavy snows
or ice storms may cover up what little is left. The generaliza-
tion can still be made with comparative accuracy that the year
to year winter carrying capacity of environments for bob-white
in Iowa and Wisconsin is not proportional to the amount of
food. On most farms we have observed, there was usually, dur-
ing open winter weather, food enough to feed many times the
peak number of quail that we have found, and enough more to
feed the variable numbers of small birds and small mammals
which occurred there as competitors. The distribution of the
food with respect to cover and covey territories is of infinitely
greater significance than sheer quantity. Tremendous quan-
tities of food may exist in the fields of a given farm, but in
places available to few if any bob-whites.
•
A certain amount of food must be available to make bob-
white territory habitable, and a certain amount must be suffici-
ently available at all times to carry populations through winter
crisis. But if the food supply is ample and available and prop-
erly distributed, further increase is not attended by a corres-
ponding rise of environmental carrying capacity for quail. Con-
versely, if the food supply is far in excess of the needs of the
wintering populations, it can stand considerable reduction
without affecting carrying capacity.
383
דו
I
COVER AND CARRYING CAPACITY
Food is the first essential constituent of a winter quail terri-
tory; cover is the second. The quality, distribution, and con-
venience of food and cover, together with the bob-whites' intol-
erance of crowding, probably determine in largest measure the
carrying capacity of environment for the species.
Some food of adequate quality must always be available to
quail in a habitable territory, for the birds cannot eat the cover.
If the food supply is deficient, the birds cannot occupy a given
territory in the first place, or will be forced out later; if it fails
for any period exceeding a very few days, severe mortality may
result. Emergency conditions are much more likely to be pre-
cipitated by lack of food than by lack of cover.
But quail losses through lack of cover, while almost never
of the cataclysmic magnitude of some losses through lack of
food, nevertheless constitute a steadier drain and one seemingly
of greater significance in the determination of year to year
population levels. Indeed, environmental carrying capacity for
winter bob-whites seems basically to be a matter of cover
limitations as much as anything else. The lethal character of
territory number 14 was apparently due to cover deficiency, and
cover may conceivably be the factor limiting carrying capaci-
ties of many non-lethal territories or those which are lethal
only to the degree that they are over-populated.
Cover is of value to the bob-white chiefly as protection or
concealment in ca Lattack by enemies. Lack of cover means
vulnerability to
on, whether enemies are few or many.
Cover has also a ain value as shelter during periods of wet
or cold weather, or during storms, but the necessity of shelter
for the bob-white is usually over-rated by the public about as
much as the necessity of escape cover is under-rated.
In any discussion of the efficacy of the various cover types
in affording concealment or mechanical protection to quail, the
role played by weather should not be overlooked. The actual
utility of many cover types hinges upon whether there is much,
little, or no snow. A heavy snowfall, for example, may not only
bury the principal food supply and thus make a given territory
uninhabitable, but it may also bury the principal cover and
make the territory uninhabitable from that standpoint as well.
A heavy glaze of ice may have a profound effect upon cover,
particularly upon grassy and low herbaceous types.
The adverse effect of deep snow upon adequacy of cover is
especially evident when the chief cover provides better oppor-
tunities for escape by hiding than by flight. Stubble, low
growths of weeds or grasses, dry leaves, hummocks, stumps,
clods, or merely unevenness of terrain may serve more or less
well for concealment in open winter weather, but the bob-white
can not use this sort of cover when it is buried under snow.


384
Dry snows reduce the concealment value of cover much
more than do wet snows. In some instances, wet snows, by
accumulating on the tops of marsh or heavy weedy growths,
furnish such an effective broken canopy that the concealment
and refuge value of the cover may even be enhanced thereby,
if the vegetation does not settle too much under the added
weight. Wet snow upon ordinary brushy cover (fig. 7) has an
undetermined but not necessarily adverse effect upon cover
value as long as it sticks to the branches; if it settles down, it
detracts considerably from the utility of the brush as cover
for quail; if it melts soon, as wet snows commonly do, patches
of leaves or dark vegetation appear here and there, and the
difficulties of quail in finding concealment are correspondingly
diminished. By and large, cover is distinctly of most advantage
when there is no snow (fig. 8).
Drifting snows may bury much first class brushy refuge
cover and so render it as useless to quail as the concealment
cover of a similarly buried stubble field. The drifting of snow
is sufficiently uneven, however, that much cover is usually not
affected to any serious extent, and patches of bare ground are
left, notably at the bases of trees, around fence posts, and at the
tops of elevations. After a time, too, holes large enough to allow
passage of quail may take form about protruding branches and
these may lead to roomy snow cavities within.
All in all, the effect of snow on habitability of quail environ-
ment is decidedly hard to evaluate. Seasoned birds are canny
in looking out for themselves and take antage wherever
they find it, within the limits of their cal powers and
adaptability. They may resort to farm buangs, holes in the
ground or in snow banks, dumps, rolls of wire, scrapped auto-
Fig. 7. Wet snow upon certain types of cover may form canopies under which bob-
whites may find good concealment.

385
Fig. 8. The efficiency of cover is usually best when there is no snow.
mobiles or farm machinery for refuge if they have to. They
may live in corn shocks or in the middle of a cornfield, quite
away from any brushy cover. They may be found in any num-
ber of unexpected and unorthodox places and may be living
there with comparative security, when there is snow as well
as when there is not.
Bob-whites are no real sticklers for rules. They live if they
can and where they can, as do other wild creatures. Like other
wild creatures, they have traits and adaptations of positive,
negative, or indifferent survival value. On the whole, they may
be said to give very good account of themselves. They may at
times exist in the face of incredible obstacles, but they cannot
be expected to do it regularly.
The mere fact that quail have been known to live in a vir
tually coverless cornfield, or to find refuge in a woodchuck hole
or a drain tile, or to escape enemies by diving into leaves or
soft snow, does not alter the fact that, in the main, they must
.have effective brushy cover within access of wherever they
may have to feed. This they must have, so far as we have been
able to determine, not only if they are to thrive but if they are
to exist at all.
For purposes of this bulletin, cover types may best be
classified according to their mechanical qualities rather than
according to the systematic position of the plants composing
them. When the systematic composition of a given cover type
is mentioned, it is only to aid the reader in visualizing the
characteristics of the cover. Bob-whites seem to care little if
a winter refuge thicket is made up of raspberry canes, plum
brush, or something else, as long as it serves their needs.

386
Fig. 9. An effective combination of brushy and weedy bob-white cover.
Likewise, the birds care little whether man may classify
their chief cover as herbaceous or brushy, but no hard and fast
separation should be made here. Dense weeds and dense brush
make a very effective combination (fig. 9), appreciably more
effective than either weeds or brush alone.
The more bare the ground appears under winter conditions
the less it provides
concealment or ref-
uge for bob-white. A
closely grazed grass
pasture is nearly at
the bottom of the
scale (foreground fig.
10); next is short-cut
stubble and hay
fields, golf greens,
park lawns, etc.
Heavy grasses, espe-
cially in relatively
ungrazed low spots
(fig. 11), represent
choice cover for
night roosting as
well as for daytime
concealment.
Growths of sweet
clover (Melilotus
spp.), goldenrod
(Solidago spp.),
Fig. 10. A closely grazed pasture furnishes poor
cover in winter.

387
Fig. 11. Good cover for night roosting and daytime concealment. The brush adds to
the value of the grass for this purpose.
ragweeds (Ambrosia spp.), lamb's quarters (Chenopodium
spp.) and vegetation of this general consistency and habit (fig.
12) may
offer good concealment but not too adequate mechan-
ical protection, unless supplemented by brush as in figs. 11 and
15. Dense stands of burdock (Arctium minor), marsh elder
Fig. 12. Growths of goldenrod-sweet clover type-furnish better concealment
facilities than mechanical protection.

388
Fig. 13. Open brush, as sumac, may be distinctly inferior as winter quail cover.
(Iva spp.), hemp (Cannabis sativa) and other coarse weeds
may sometimes give as effective mechanical protection to quail
as many of the brushy cover types.
The more open brushy cover types such as Sumac (Rhus
spp.), may, in fact, be quite inferior to heavy weed growths as
refuge to quail (see foreground of fig. 13). Better cover is
afforded by willow (Salix spp.), osier (Cornus spp.), alder
(Alnus spp.) and suckers growing from stumps of hardwood
trees, though here again the value of the cover is less dependent
Fig. 14. Rather ineffectual brushy cover (compare with fig. 15).

upon its taxonomic position
than upon its effectiveness in
impeding pursuit by ene-
mies. (Compare the open
cover of fig. 14 with the
dense mat of brush in fig. 15;
in both pictures the cover is
made up of about the same
plant species.)
389
The quail cover on wood-
ed hills shown in fig. 16 is
only fair in quality, as may
be said of most predominant-
ly timber growths. The brush
about the base of the hill,
however, is of good cover
quality and is similar to the
raspberry (Rubus spp.) and
sapling growth of fig. 17.
The mixed stand of trees and
brush illustrated by fig. 18
constitutes superior decidu-
ous cover of a type frequent-
ly found around the edges of
woodlots and in localities where the practice of over-grazing
is not prevalent.
Fig. 15. Cover of brushy plant types simi-
lar to those of fig. 14 but greatly strength-
ened by tangles of brush and by heavier
herbaceous vegetation.
Roadside brush (fig. 19) may be of extreme utility to quail
if of sufficient thickness. In this picture, the growth is largely
Fig. 16. Fair quality cover on wooded hill. The brush at the base of the hill, however,
is superior and similar to that shown in fig. 17.

390
Fig. 17. Cover of good quality (a mixture of saplings and raspberry canes) fringing hill.
raspberry with some grapevine (Vitis spp.). The dark clump
to the upper left of the picture represents a fine stand of leafy
oak (Quercus spp.) suckers. Roadside brush has the disad-
vantage of drawing quail to places where they may be potshot
from automobiles, and it is rarely safe from destruction by man
Fig. 18. Superior deciduous cover of the type found about the edges of ungrazed woodlots.

391
Fig. 19. Roadside brush constituting effective quail cover. This growth is made up
largely of raspberry canes and grapevine.
for any period of time. Thickets of haw (Crataegus spp.), plum
(Prunus spp.), and mixed vegetation of many kinds (fig. 20)
may add greatly to the habitability of a given quail territory.
Massive tangles of vines not too far from the ground are
notably desirable as escape cover.
Fencerow growths of grapevine mixed with other vegeta-
Fig. 20. A roadside thicket valuable to wintering bob-whites.

392
tion have proved to be highly superior cover on many of our
observational areas. Scraggly fencerow growths, of course,
occur and are worth little or nothing as cover, but a substantial
tangle of years' standing may be a bulwark of protection for a
covey which has no other place of refuge. Fencerow growths
seem not so likely to be disturbed as roadside growths, and for
that reason may be of superior value.
One of the best cover types of all is sometimes found in
communities in which most of the other cover has been grazed
off, i. e., the mats of creeping juniper (Juniperus communis
depressa), conspicuous in non-glaciated south-western Wis-
consin (fig. 21). It is commonly mixed with red cedar (Juni-
perus virginiana, a plant likewise resistant to grazing but
one of less value from the standpoint of quail cover) and often
redeems a given tract of land from utter hopelessness as quail
environment. Dense mats of creeping juniper made up the
principal cover of territory number 29.
Brush piles, if roomy inside and of fair size, furnish
exceptionally good escape facilities and greatly enhance the
value for quail of almost any cover vegetation. They may be
especially effective if carefully constructed for the specific
purpose of providing quail cover at strategic places (fig. 22).
Brush piles which have settled flat through decay may be of
scant use to desperate bob-whites.
RELATION OF CARRYING CAPACITY AND COVER
In the construction of the cover relationships map of the
Class One to Three Prairie du Sac territories (fig. 23), an
Fig. 21. Mats of grazing-resistant creeping juniper may serve to make habitable for
quail many tracts of pasture in dairy communities.

393
Fig. 22. Artificially constructed brush-piles at strategic situations may often hold quail
coveys in places that otherwise would not be occupied. Brush-piles are recommended
for over-pastured woodlots.
enlargement taken from a U. S. Geological Survey folio was
used as a base, and the cover types were filled in from the field
with as much detail and accuracy as time and lack of skill and
instruments permitted. The map has its crudities, but it should
give a fair idea of the general physiographic features of the
area, the juxtaposition of usual feeding ground (cultivated
land) and possible escape or concealment cover and the relative
proportions of cover types to each other.
While the map represents specifically the cover conditions
as they existed during the winter of 1934-35, it also depicts
fairly well the conditions for all other winters back to 1929-30,
with the exception of the winter of 1933-34, when all of the
roadside brush was cleaned up by the CWA. The food condi-
tions have not shown the comparative year to year constancy
that the cover conditions have, although broadly the same
tracts of land have been cultivated year after year. On the
whole-barring drouth, snow, or fall plowing-the food con-
ditions on the various territories have not shown much change
during the six winters of intensive observation.
After scrutiny of the map (fig. 23), we must confess that
we fail to see much correlation between limits of carrying
capacity and the gross quantity, quality and distribution of the
cover.
394

COVER TYPE LEGEND
GROUND JUNIPER
VINE TANGLE
DENSE BRUSHY GROWTH
GOOD DECIDUOUS COVER
FAIR DECIDUOUS COVER
DOOR DECIDUOUS COVER
DENSE WEEDY GROWTH
FAIR HERBACEOUS COVER
SCANT HERBACEOUS COVER
-z+-n-
VIRTUALLY NO COVER
WITH SNOW ON GOOUND
(MAINLY CULTIVATE
FIELDS)
-WHE⋅
JI
WISCONSIN
**
XMILE
"D
*****
--800
XMILE
TERRITORY
#20
#900
TERRITORY
COMBINATIONS
OF
#.5&#13.
400
TERR
1
XMILE
Yo.....
IMILE
RIVER
…………………..
******
TERRITORY #29
900
TEC
TERRITORY
COMBINATION OF
#6 #12 #15
#16 #54
1111
395

RITORY
900
900
Η
TERRITORY
ICOMBINATION
OF
#4 #17 #18
#19
CARRYING CAPACITY
OF TERRITORIES ON THE BASIS OF
MEDIAN SURVIVAL 1929 -1955
TERRITORY
#14
TERRITORIES
-20
#20
#||
#14 (LETHAL)
ડમડ
#6 #12 #15 #16 #5 4
#4 #17 18 19
CATED S
MEDIAN
SURVIVAL
16
✦
21
30
O
105
53
59
17
• •*********
CLOSEON
Fig. 23.
396
We know, at one extreme, that quail may winter in corn
shocks or even in rather open fields. We know that some con-
sistently quail-vacant or lethal territories may have more cover
than some of proven habitability. We know that artificial im-
provement of cover may not necessarily raise carrying capacity,
and we know that a great deal of debrushing and "cleaning up
may not necessarily lower carrying capacity.
""
We do know, on the other hand, that carrying capacity has
been both raised and lowered by changes in cover conditions.
Environmental manipulation, for one purpose or another, may
often be of profound consequence to bob-white populations, but
we see no way of predicting its effect in advance. To be sure,
we may predict with reasonable certainty that a strong spread
of fencerow and roadside brush in central Iowa may be fol-
lowed by an increase of quail and that any wholesale reduction
of existing cover would probably mean decidedly fewer quail,
but there is a great deal about this that we do not know,
especially as to details.
Leads as good as any perhaps may be given by the data
from territories number 11, number 17 and others where rela-
tively slight environmental modifications have made territories
unattractive, if not lethal. The cleaning out of one small but
strategically located patch of roadside growth apparently
changed number 13 from a habitable to a lethal territory. The
burning of a single brush-pile, likewise strategically located,
patently left territory number 11 with an altered status, so far
as wintering quail were concerned.
From data of this sort as well as from the stability of carry-
ing capacity so frequently maintained by bob-white territories
despite changes in the cover equation, we may be tempted to
conclude that only the cover in certain portions of a territory
may be significant. In a number of instances, territories have
been studied in some detail with reference to the daily routine
of resident coveys, but so far there seems to be nothing which
habitable territories may be said to have in common except
food and cover sufficient for the rather variable needs or
preferences of the birds. A territory simply seems to be ade-
quate if the birds like it and can live there, whatever may be its
score when judged by human standards.
C
We may go a bit further and postulate that the instinctive
reactions of the quail themselves to the "lay of the land” in
times of sudden crisis may be a partial answer. It is quite con-
ceivable that certain coverts may have strategic importance to
the bob-whites, not so much because of any singular qualities
which they may have as coverts, but because the quail may for
some reason tend to use them. It is conceivable also that
strategic coverts may be inferior both in quality and in accessi-
397
bility to non-strategic coverts but may be strategic solely
because they may be the ones used when the quail are hard
pressed by enemies.
The detailed determination of what constitutes habitability
for wintering bob-whites does not present the theoretical
difficulties offered by the determination of what governs
definiteness of carrying capacity, still assuming that such a
thing exists. We may, in the not too distant future, be able to
evaluate the constituents of an environment and say with
reasonable certainty that it is or is not habitable for quail; but
whether we may ultimately, without survival records, be able to
tell within a bird or two what is the carrying capacity of a
given territory is another matter.
Stoddard (letter, Aug. 27, 1935) feels that the time required
for quail to fill their crops is of vital importance, especially
when snow is on the ground. He considers quail most vulner-
able to accipitrine hawks while feeding. This is doubtless true,
but probably greater winter losses from predation are suffered
by northern quail at hours when they are not feeding, notably
at night.
One of the greatest obstacles in the way of theoretical ex-
planation of definiteness of carrying capacity is the fact that
the predation which reduces the surplus is of several different
types. If the predation were due entirely to foxes, or entirely
to Cooper's hawks or entirely to something else, some sort of
plausible hypothesis might take form. But these predators all
have more or less different hunting techniques, yet their net
collective effect seems to be about the same; in the absence or
scarcity of some important predatory species, the pressure of
others seems to compensate. Why should only about so many
bob-whites be able to survive in a given territory, seemingly
irrespective of the kinds and numbers of predators?
Difficult as it ordinarily is to trace a substantial proportion
of quail kills to specific predators, it is still more difficult to
witness the actual killing or to reconstruct with satisfactory
accuracy and completeness the story of the event. Data of this
sort trickle in with extreme slowness, but they do come, never-
theless; and in the aggregate, over a period of years, partially
answer some questions and raise a great many more.
From the data we have, it seems that foxes usually get
winter bob-whites when individuals are separated from the
covey and are hiding singly, either on the ground or in tufts of
grass. Cooper's hawks may catch birds by surprise while they
are on the ground or overtake them if they have too far to fly
to suitable cover. If the refuge cover is inadequate, the pur-
suing Cooper's hawk may follow its prospective victim on
foot. Marsh hawks make captures by flying low over fields and
suddenly dropping on birds which they may find practically
within reach when visibility is poor. Horned owls, in the main,
398
seem to get birds that are wandering about in the dark, and
especially those that have been night-flushed to alight in
exposed places, such as snow covered open hillsides. How less
efficient predators get healthy adult winter bob-whites, except
through cornering them by chance, we do not know. When the
birds are from some cause too weak to fly, there is less mystery
about how they may be caught by any predator, whether of
regularly formidable or commonly inconsequential type.
There doesn't seem to be anything of exact similarity in the
hunting tactics of any of the principal types of predators. Still,
the net result of the pressure of all of these seems not to differ
materially from the net result of the pressure of any one in the
absence of the others, although they are not all capable of re-
ducing quail surpluses with uniform rapidity. For example, it
might take most of the winter for foxes to reduce a given over-
population which Cooper's hawks could consume in a week or
two.
The role of education in determining the reaction of quail
to predators is not as clear as it might be. There is some
reason to believe that some of the early winter losses may be
due not so much to over-population as to unwariness of some
of the birds, possibly the younger ones. It is quite apparent
that sometimes a lesson-such as the loss of a member of the
covey to the supremely dreaded Cooper's hawk [Errington
(13)]—may be needed to put a covey on guard, and the lesson
may be needed in mid-winter as well as in the fall. The data
which we have indicate that secure bob-white coveys will not
suffer appreciably more from a moderate wintering population
of Cooper's hawks than from perhaps a single individual
drifting through in the course of the winter. All in all, we are
inclined to include the "educational" winter losses with the
immaterial 5 or 6 percent previously discussed rather than with
the losses through over-population, which concern us mainly.
But for all of the heterogeneity of the predation data, one
thing does seem to make a certain amount of sense: An exten-
sive, dense, thicket tangle adjacent to an adequate and conven-
ient food supply is an excellent all-around protection from
enemies collectively. Even so, the strongest natural coverts,
artificially strengthened further by sizable brush piles with
grain within, seemingly have a limitation of carrying capacity
far below the actual feeding and refuge facilities they make
available to wintering bob-whites.
TERRITORY AND CARRYING CAPACITY
We shall make no effort in this writing to review the litera-
ture dealing with the natural means by which animal popula-
tions are held in some sort of check. It is evident enough that
no species may actually continue to increase year after year
399
indefinitely and bring young to maturity at rates comparable to
its theoretical reproductive potential.
Elton (10) in critically discussing the "balance of nature"
concept says, "Now, I suppose the picture of the internal
arrangements of an animal community that is most frequently
drawn for us is one in which the powerful tendency to increase
in numbers which is possessed by every species is exactly can-
celled out by some effective controlling factor-for many
animals their enemies, for others also the climate, food supply,
breeding places, and so on . . . . . it is assumed that an un-
disturbed natural animal community lives in a certain harmony,
referred to as 'the balance of nature', and that although rhyth-
mical changes may take place in this balance, yet that these are
regular and essentially predictable, and, above all, nicely fitted
into the environmental stresses without."
He continues, “The picture has the advantage of being an
intelligible and apparently logical result of natural selection in
producing the best possible world for each species. It has the
disadvantage of being untrue. The balance of nature' does not
exist, and perhaps never has existed. The numbers of wild
animals are constantly varying to a greater or less extent, and
the variations are usually irregular in period and always irregu-
lar in amplitude."
-
Nevertheless, while the "balance of nature" may not be
everything it has been thought to be, the fact should not be
overlooked that biotic equilibria of some sorts do exist. For
example, Chapman (5 p. 188) has experimentally demonstrated
for the flour beetle (Tribolium confusum) that, "after a period
of approximately 100 days, the number of individuals, as
expressed in beetles per gram of flour, becomes constant at
about 43.97 individuals per gram and fluctuates about this
number." He found that there were wide fluctuations in egg
numbers but not of adult populations and that cannibalism was
the mechanism of control. "At low concentrations, eggs and
pupae escape and develop to become adults. When many of
them have developed into adult beetles, the concentration is
then so high that relatively few eggs or pupae are able to
escape; and the population then remains constant."
[For further discussion on the general topic of animal
population limits the reader is referred to Allee (1).]
Howard's (42) work on territorial relations of nesting birds,
mainly passerines, has probably done as much as anything to
open up a new field of thought and to stimulate research on the
role of territorialism in vertebrate ecology. At the present
time, a great but rather belated interest in this phase of bird
study has been manifest. Nice (62) states, "The recognition of
territory in bird life has been epochal in its effect on students
of the biology of birds; the science of life history study has
400
been reoriented thereby in the last dozen years." Nice (63,64,
65, 66) through her studies of the song sparrow (Melospiza
melodia) has contributed materially to the science in this
country and has significantly reviewed the literature on the
subject (62).
And, although Nice (62) cautions that "the latter [the bird
students of the world] are in danger of going territory-mad,"
it is evident enough that the ecological exploration of the field
has barely begun. The concept of "home range" for vertebrate
species is now anything but new, but what does it signify, what
is its importance in the determination of population levels?
A partial answer is expressed by Nicholson (67): “When
animals lay claim to territories.
it is clear that in any
given area there is room for only a limited number of terri-
tories. Consequently, the surplus individuals are continually
harried by their more fortunate brethren, or are forced into un-
suitable environments, and so their chance of survival, and of
producing offspring, is greatly reduced. The system of balance
resembles that of water in an overflowing reservoir . . .
Nice (62), endeavoring to discourage loose usage of the
term "territory," says in the summary, "Territory implies in
the male bird isolation, advertisement, fixation, and intolerance.
Where these four aspects are not present, the bird does not
truly hold territory. . . . It may be that the food aspect of
territory has been over-emphasized, and that sex jealousy in
many cases plays a definite part."
It is rather evident at this time that the role of food in
governing animal population levels generally has been and is
still very imperfectly understood, and certainly has not the
precise general importance formerly attached to it by many
naturalists of the Malthusian school. McAtee (60) in particular
points out that relatively few organisms increase up to the limit
of their food supply, save under exceptional conditions.
That territorial intolerance, or at any rate, over-crowding.
may have manifestations not explainable by present knowledge
is surely to be expected. There seem to be, among other
things, psychic or physiological inhibitions which serve to slow
breeding rates as populations approach saturation densities.
""
Kendeigh (44) believes, for the house wren (Troglodytes
aedon) in Ohio, that "the number of broods per female per
season tends to vary inversely with the total population"; also
"This compensating reproductive resilience may not become
effective the same year as a major calamity
Nice (letter
Aug. 22, 1935) is not sure of this point, however, and states
further regarding her own specialty, another small passerine
bird, the song sparrow: "Although the population on Interpont
has varied in the past six to seven years between 33 and 87
pairs, the average number of eggs laid in a set has barely varied
at all."
•
رو
401
R. T. King (unpublished) has observed at Cloquet, Minn.,
that the size of ruffed grouse (Bonasa umbellus) egg clutches
diminishes with rise of population density during the upgrade
of the cycle.¹¹
Up to date, the vast preponderance of literature on verte-
brate territorialism has dealt with population relationships dur-
ing the breeding season. The term "territory" has all but come
to have an accepted meaning of breeding territory among
ornithologists, but we see no valid reason why the usage should
be so restricted.
There is an evident fixity of range found in some non-breed-
ing populations outside of the breeding season; there are on
such ranges individuals or groups of individuals which are at
least to some degree isolated and to some degree intolerant of
other individuals or groups; and, while there may not be con-
spicuous advertisement such as occurs in the breeding season,
the residents may not be hesitant about making their presence
known to trespassers from the outside.
In the case of the bob-white, the birds seem to have an
awareness of when their winter territories become over-popu-
lated, either with their own species or with mixtures of their
own species and others as the ring-necked pheasant. Apart
from direct predation, the chief mechanism by which over-pop-
ulations are reduced in a given area seems to be that of de-
parture of the surplus birds. Much of the departure especially
during the winter months-seems to be voluntary, but the
indications are that strife between fall coveys [Errington (24)
and unpublished] may have a role in the establishment of
winter territories.
It is, of course, true that the fighting between coveys in the
fall may be the natural outcome of the meeting of strangers and
may be an early stage in the establishment of a pecking order.
A certain amount of friction occurs within wild coveys through
the winter, which, with the other evidence, may suggest
inequalities in the social scale. One observes apparent outcasts
now and then, or at any rate single birds in strong condition
which have stationed themselves near but apart from roosting
or resting covey groups. Are these single birds strangers,
unpopular individuals, or some simply unable to look after their
own interests, or undesirous of too close intimacy with the
others?
We cannot say whether the frequent adjustment of covey
11. The phenomenon of cyclic or periodic fluctuations of animal populations is of
extreme importance biologically. It effects conspicuously populations of rodents,
rabbits and grouse in northern regions, but neither its causes nor its influences are well
known. There is some evidence that the bob-white, among other species, may be
subject to periodic as well as irregular fluctuations, though this as yet has been investi-
gated too imperfectly to justify much opinion. For literature on animal cycles the reader
is referred to Elton (8, 9, 10), Leopold (48), Green and Schillinger (39), Severtzoff
(69), Wing (77), Matamek Conference on Biological Cycles (61).
402
numbers to conform to the carrying capacity of the wintering
territory is precipitated by predator pressure from the outside,
though not necessarily pressure of sufficient intensity to be
lethal before adjustment occurs.
The strongest probability is that consciousness of crowding
plays an important part in the general distribution of the quail
population in the wintering territories, but that the specific
self-adjustment of covey numbers to the carrying capacity of
environments with such frequent exactness is forced. If it were
due only to a vague uneasiness on the part of the covey as a
whole that too many birds were present, one might expect
some birds of the covey to split off and leave. If it were due
only to a feeling on the part of dominant birds in the covey that
the covey should not exceed a certain size, they could con-
ceivably keep it from exceeding that size by punishing out the
excess. But the fact that carrying capacity seems to have such
a definite value, season after season, and that mortality follows
over-population of even minor degree, is far from being explain-
ed entirely in terms of species behavior, or territorialism. That
these have influence in the winter equation, however, seems
quite evident.
BIOLOGICAL APPLICATION OF POPULATION
VULNERABILITY
In the first place, we may admit that we do not know what
is responsible for the definiteness of environmental carrying
capacity noted for wintering bob-white. We are not so sure
that carrying capacity is such a definite thing as the present
data indicate, or that a population entrenched with ordinary
security in an environment would be secure against all natural
enemies with which it could conceivably be confronted.
Armed and ingenious man has often demonstrated his
ability to reduce populations that live in comparative security
from other directly predatory enemies. Man may be supremely
efficient as a predator when he wants to be, in which respect
he cannot even be approached by wild predators. Stoddard
(letter, Oct. 4, 1933) thinks that Cooper's hawks may still get
quail when they are safe from about everything else, and also
that the goshawk (Astur atricapillus) may be a still more
formidable enemy on the occasions of its infrequent visitations
from the north. In our studies, we have never personally had
the opportunity to witness the work of goshawks upon quail,
and the pertinent data we have are second hand [Errington
(19)]. The goshawk, however, may be looked upon as a sort
of super-Cooper's hawk (the female Cooper's hawk almost
equals the male goshawk in size), and surely any superiority of
its prowess is only one of degree.
But whether carrying capacity of specific bob-white winter
403
environment is really definite or not, populations exist which
are so securely situated that even modern man has difficulty in
taking much of a toll by direct pressure, even in the course of
long hunting seasons. We have known Cooper's hawks to
harass certain well situated coveys for weeks at a stretch with
out getting any of their members, or getting at the most a very
few birds in the course of the winter.
McAtee has recently restated his thesis that predation
tends to be in proportion to population (56) to the effect that
the proportion, however, rises and falls progressively with the
increase or decrease in numbers of the available food organisms
(58). Errington (31), for reasons evident from the bob-white
studies, suggests that predation may be in some cases propor-
tional to over-population instead of to population; he also raises
the question if many animal populations may not in analysis be
composed of vulnerable over-populations and secure residua,
which residua, nevertheless, may not necessarily be insignifi-
cant numerically.
Indeed, it seems as if any number of species may live in
relative security from predators at given population levels in
given habitats. Errington (MS accepted by Canadian Field
Naturalist, 1935) presents some evidence that very low popula-
tions of ruffed grouse in marginal environment may be thus
maintained with little change during the winter months,
though Gardiner Bump (letter, July 15, 1935), from investiga-
tions in good ruffed grouse country, writes: "All in all, I do not
feel that in New York adult grouse populations within the car-
rying capacity of the range exhibit any significant security of
position." On the basis of unpublished and fragmentary local
evidence, we suspect that the muskrat (Ondatra zibethica) may
also belong in this category, at least under some circumstances.
Tinbergen (75), studying the food habits of the Waldoh-
reule (Asio o. otus) and the pressure of this owl upon Microtus
arvalis, concludes that the control of mouse populations by
predation is most effective at what we understand to be moder-
ate levels; rises of prey populations toward top-heavy peaks
plainly get out of control.
Gause (36) quotes Kalabuchov and Raewski on observa-
tions made in the North Caucasus: "The picture of the destruc-
tion of mice by different predators is a curious one. At the
beginning of the destruction about the same number of rodents
is devoured daily. But as the density of rodents diminishes it
becomes more and more difficult to catch them, and the number
of mice devoured gradually decreases. Finally a time comes
when the relation between the density of the rodents,
the presence of cover or refuge (burrows, vegetation,
etc.) and the biological peculiarities of the predators become
such that the latter can devour the rodents only in rare cases.
In this way the number of the rodents remains constant."
404
This represents population vulnerability of a staple prey
species rather than an incidental prey species as the bob-white.
Species in one category seem to be characterized by secure
residua that may be very small compared to the population
levels commonly reached and, at the same time, characterized
by comparatively tremendous over-populations of vulnerable
individuals. At the other extreme, we may have species usually
characterized by large secure residua and small or negligible
over-populations. From one extreme to the other, we may
expect that some entire animal populations as they may occur
in nature-particularly as adults-may consist almost wholly
of over-populations or almost wholly of secure residua, with all
intermediate gradations. Whether or not the numerical ten-
dency of a strong species is toward habitual over-populations,
or towards levels of greater stability, seems to depend upon how
strictly its increase may be controlled by limitations of environ-
ment.
We do not imply that population vulnerability has univer-
sal biological application. We do not know what may be its
application. It is apparent, however, that all vertebrate species
are not wholly vulnerable in the same way or at the same stages
of their life histories. We are not in the least sure that all
species have secure residua at any population level, high or
low.
That population vulnerability may to some extent apply
to avian nests and young more than to adult populations is
indicated by recent wild duck breeding studies carried on by
Iowa State College staff members in north-western Iowa,
chiefly by Logan J. Bennett. Our experience has been that
most of the duck nests exposed on account of human meddling,
mowing, close grazing, insufficient natural cover, precarious
locations, etc., were likely to be destroyed, irrespective of the
presence of particular predators, including the highly unpopu-
lar crow (Corvus brachyrhynchos).
"Similarly, we suspect from limited observations that crow
depredations upon ducklings may be largely linked with
exposure. It is not surprising that many instances have been
reported from drouth regions. Small ducklings forced into
shrinking puddles with yards of sticky mud between them and
the nearest cover are truly in a bad way. Crows may get them
or marsh haws [may] or other flesh eaters, or they may
mire down or die of thirst. . . . Depredations may be more
correctly a matter of how many ducklings are ready to
be picked off rather than one of few crows or many crows
The basic principle underlying predation is availability of prey"
[Errington and Bennett (34)].
•
Logan Bennett (6), comparing two duck nesting seasons in
the vicinity of Ruthven, Iowa, estimated that in 1934 over-
405
grazing and drouth destroyed 75 percent of the nesting cover
on lands where the nesting conditions had been excellent in
1933. In 1933, only 15.3 percent of 137 nests were total failures;
in 1934, 64 percent of 103 nests were lost from all causes, includ-
ing enemies which found the ill-concealed nests much more
available.
Nice (letter, Aug. 27, 1935) writes regarding song sparrow
populations". during the first two years on Interpont
the survival of the birds was splendid-over 60 percent with
the males, but now that it has been destroyed, the survival has
fallen as low as 23 percent. Apparently the birds will take up
these territories that prove lethal to them-partly through
attachment to a former territory, even when considerably
changed, partly probably because there is so little really good
song sparrow territory anywhere in the vicinity." [See Nice
(66) for a more detailed discussion.]
In short, while it is not always easy or even possible to dis-
tinguish with exactness between mortality due to predators or
due primarily to something else, it is apparent that no predator
will prey upon an animal which it is unable to get, whatever
may be the precise reasons for its inability to do so.
PART IV. MANAGEMENT OF THE BOB-WHITE'S
WINTER TERRITORY
MANAGEMENT AND ITS OBJECTIVES
"Wildlife management" implies a less passive technique
than the older term, "conservation." It lays more emphasis.
upon the improvement and maintenance in an improved condi-
tion of environment for wild species and less emphasis upon
legal protection and the establishment of sanctuaries. As the
term is used here, management does not mean artificial propa-
gation. It means the encouragement of wild species under con-
ditions as nearly natural as possible. Management is applied
ecology. It is human manipulation of wild populations and may
be motivated by economic, aesthetic, or scientific objectives.
From the beginning of settlement in North America, the
white man has manipulated wild populations, though not
always consciously or always with definite intent. His agricul-
tural and commercial practices and exploitation of available
resources have profoundly altered the habitats and the numer-
ical status of the wild species which he found here. The mere
fact that many of man's manipulations have been blind does not
lessen their ecological significance, nor does the fact that man
may not be qualified to judge what is to his interests, or that
his interests may be narrow, selfish, or shortsighted.
Man will unquestionably continue to manipulate for his own
ends his own environment and that of other living creatures.
406
His manipulations may be conservative, as befits those of a
thinking being, or they may be little more than meddling with
mechanisms which he neither recognizes nor appreciates. His
own destiny is dependent to no slight degree upon how he
manipulates.
To quote from Leopold (48) on the social significance of
game management: "The game manager manipulates animals
and vegetation to produce a game crop. This, however, is only
a superficial indication of his social significance. What he really
labors for is to bring about a new attitude toward the land.
"The economic determinist regards the land as a food
factory. Though he sings 'America' with patriotic gusto, he
concedes any factory the right to be as ugly as need be,
provided only that it be efficient.
"There is another faction which regards economic produc-
tivity as an unpleasant necessity, to be kept, like a kitchen, out
of sight. Any encroachment on the 'parlor' of scenic beauty is
quickly resented, sometimes in the name of conservation.
"There is a third, and still smaller, minority with which
game management, by its very essence, is inevitably aligned.
It denies that kitchens or factories need be ugly, or farms life-
less, in order to be efficient.
"That ugliness which the first faction welcomes as the
inevitable concomitant of progress, and which the second
regretfully accepts as a necessary compromise, the third rejects
as the clumsy result of poor technique, bunglingly applied by a
human community which is morally and intellectually unequal
to the consequences of its own success."
That the necessity for a more harmonious relationship
between man and his environment is no longer something to
concern only the aesthete should be apparent from the ever-
growing menace of soil erosion. H. H. Bennett's (2, 3), Dar-
ling's (7) and Taylor's (74) writings are fraught with ominous
meaning, and the lesson may hardly be missed that the wages
of continued waste are ruin.
<<
Leopold (49) warns that "Civilization is not . . the
enslavement of a stable and constant earth. It is a state of
mutual and interdependent cooperation between human
animals, other animals, plants, and soils, which may be disrupt-
ed at any moment by the failure of any of them. Land-despoli-
ation has evicted nations, and can on occasion do it again
It thus becomes a matter of some importance, at least to our-
selves, that our dominion once gained, be self-perpetuating
rather than self-destructive."
At once an indictment and a prayer, we find the concluding
paragraph of Leopold's admirable pioneering text on game
management (48, p. 423):
"In short, twenty centuries of 'progress' have brought the
average citizen a vote, a national anthem, a Ford, a bank

407
account, and a high opinion of himself, but not the capacity to
live in high density without befouling and denuding his
environment, nor a conviction that such capacity, rather than
such density, is the true test of whether he is civilized. The
practice of game management may be one of the means of
developing a culture which will meet this test."
It is the integration of human ends that game management-
or more broadly, wildlife management-implies which bears
social promise. Management, to have the fullest social promise,
must mean more than the taking of what is to be taken; it must
mean a closer real harmony between man and land, between
man and other living creatures of the land. Management must
be socially and biologically self-sustaining, for, governed by
any standards other than those of permanence, it becomes only
exploitation, whatever it may be called. And the handwriting
on the wall should be clear enough at this time to tell us that
we as a nation or as a species have had about enough of ex-
ploitation.
INTEGRATION OF ENDS IN LAND USE
Leopold writes (51): “. . . . For the last half century there
has grown up a widespread conviction that our whip-hand over
nature is no unmixed blessing. We have gained an easier living,
but in the process of getting it we are losing two things of pos-
sibly equal value: (1) The permanence of the resources whence
come our bread and butter. (2) The opportunity of personal
contact with natural beauty.
"Conservation is the effort to so use the whip that these two
losses will be minimized."
Leopold, in the same writing briefly analyzes from the
standpoint of conservation economics the problem of wise land
use. He stresses the need of comprehensive fusion of interests
and sweeping simplification of conservation law, with the
single criterion of land use: "Has the public interest in all its
resources been protected?"
No longer may destructive private land use be condoned on
the grounds that a man's land belongs to him and that he has
a right to do with it exactly as he pleases, whatever that may
be; and that whatever he does with it is his and no one else's
business. But although the social consequences of land abuse.
become increasingly apparent to thinking people, and the
necessity for integration of human ends gains recognition, the
means of integrating those ends is still to take form.
We do not presume that the answer to the ills of mankind
is anything as simple as the management of the bob-white quail.
The management of the bob-white, however, may be closely
linked with wise use of the land.
The bob-white thrives best in agricultural communities, and
408
7
its fortunes in the long run are essentially the fortunes of the
soil. Bob-white management may be to a large degree
correlated with erosion control. Management of this, as
well as other wild species of similar requirements, may reason-
ably be dove-tailed into sound agricultural practice over wide
areas of land. In the overwhelming majority of instances,
management of the bob-white may never be more than
incidental to good land use, but we fail to see why it should
not be carried on incidentally. Bob-white management, proper-
ly conducted, at least need not be detrimental to permanent
agriculture.

To the question, "Why manage bob-white?" perhaps the
best answer is another question, "Why not?"
There are many farm customs which could be modified in
behalf of the bob-white, and the chief modification often need
cost little or nothing in time, labor, money, or efficiency. A
great deal in management may be accomplished merely by head-
work, by remembering that living creatures cannot continue to
live without a place to stay and something to eat. Simplicity
characterizes some of the measures that may be quite effective
in less intensive grades of management.
The more intensive the management is intended to be, or the
less suitable is the area to be managed for bob-white, the more
difficult the management may become. In the event that an
area is to be managed to produce the maximum number of birds
for shooting purposes, field trials, etc., management may be-
come more complex and more expensive.
But the farmer who just likes to have the birds around need
not go to much trouble to insure the permanence of a covey or
two which he may have on his farm, or perhaps to establish a
new covey in some covert not previously occupied.
After all, perhaps the strongest argument for the preserva-
tion of wildlife-not solely shootable game, but all native
species that can be made to fit into our economic and social
system is the enjoyment that may be derived from their
presence, whether their presence may be of more material
benefit or not. Anything which provides a healthful diversion
from the monotonies and worries and accelerated pace of
modern life surely has a social value which should not be over-
looked.
Finally, effective bob-white management is not necessarily
a matter of what is done; more often it seems to be a matter of
what is not done. The truth and significance of this thought may
possibly be more readily appreciated when one considers that,
of the usual practices which evict quail populations from many
farms, not a few are practices which work to evict human
populations, ultimately and permanently, from the same land.

409
MANAGEMENT OF BOB-WHITE FOOD
Liebig's Law of Minimum, as restated by Taylor (73) has
application to the management of the bob-white conspicuously
when one considers it from the standpoint of food: "The growth
and functioning of an organism is dependent upon the amount
of the essential environmental factor presented to it in minimal
quantity during the most critical year or years of a climatic
cycle."
This is illustrated for bob-white by the profound effects of
killing winters on the population levels of the species over wide
areas in the northern fringes of its range. In some localities
there is starvation mortality nearly every winter, and popula-
tions rarely have a chance to attain levels which the environ-
ment could securely accommodate otherwise. Sometimes, as in
central Minnesota and central Wisconsin, a succession of open
winters permits tremendous increase of bob-whites [Leopold's
"irruptions" (48) pp. 50, 58-64]; then, a season of heavy snows
comes and the quail are gone again.
The likelihood of cataclysmic starvation emergencies dimin-
ishes with more southerly latitudes, although irregular emer-
gencies still decimate populations as far south as Missouri.
There is practically no locality in the north-central states where
starvation losses on unmanaged areas may not be expected to
recur with varying frequency.
It has been pointed out before that, while winter feeding of
bob-whites bears more promise as a management measure to
insure the security of wintering populations rather than to
raise the carrying capacity of the land, it makes whatever carry-
ing capacity there is more fully available.
There is one thing that the provision of food for a rather
unexpected emergency and for the regular use of an entire bob-
white population should have in common. In either case, the
feeding should be adequate for all the birds that need it as long
as they need it. This may not be at all or perhaps but 1 week
of the winter in an agricultural community; it may be 6 solid
months on wild lands or on lands reverted or withdrawn from
agriculture. The feeding program should always be planned
so that whole populations may be taken over "on relief," so to
speak, for periods during which, for emergency or other
reasons, the carrying capacity of the land for quail may be
suspended.
The difference in principle between providing food for emer-
gency or regular use lies in the stress that should or should not
be placed upon making the supply attractive. If man, on wild
or reverted lands, expects by artificial feeding to maintain pop-
ulations at levels found on cultivated lands, he must furnish a
satisfactory substitute for the waste grains and edible weed
410
seeds that are available incidental to cultivation. Unless he
does this, he will have at best a sparse population after the "fall
shuffle" and one that he may by no means feel certain of hold-
ing if there are cultivated lands adjoining.
On the other hand, if a great part of the management prob-
lem is not to hold the birds in a given territory in the first place,
but to insure their security in the event of emergencies, it might
be advantageous not to make the artificially supplied food too
attractive. The ideal food for such a purpose would be one
which the birds would not relish to the extent that they would
neglect the foods naturally available, and so clean up the emer-
gency food before it was most needed, yet it should be one
capable of sustaining life during severe winter weather. The
ideal emergency food should also be one which would not be
likely to be cleaned up early in the season by competing forms,
i. e., small birds, rabbits, squirrels, pheasants, livestock, etc.
Whether such an ideal food exists we do not know. At any rate,
we have never discovered it.

Corn, for general purposes, seems to constitute the best all
around winter quail food in northern states. It may or may not
be eaten as a regular staple, but even when the birds show a
preference for some other food, as the achenes of lesser rag-
weed, they readily turn to corn during crises. Adult birds have
no difficulty in swallowing the kernels and learn even to shear
away the husks to get at the ears (fig. 24).
Corn is best made available in partly open shocks strateg-
ically placed with reference to suitable cover, or left unpicked
in a few rows at the edge of a field. Squirrels and rabbits may
compete severely with quail for a limited supply, but this com-
petition may not have an entirely adverse effect. Rabbits fre-
quently make corn available to quail after ice storms by biting
through the ice glaze on the ears. Squirrels often drop quanti-
ties of kernels (with embryos eaten) at the bases of trees, where
they may be found by appreciative birds. Some coveys may
even make a round of the squirrel trees as a part of their daily
routine, and we have known coveys to depend for food upon the
corn and acorn fragments shelled out by squirrels.
Some types of feed hoppers work quite satisfactorily, es-
pecially those of simple design and those not requiring much
human attention, and especially those inside of or surrounded
by large loose brush piles. The efficacy of a feeding station de-
pends largely upon where it is placed and upon how functional
it may remain for weeks at a stretch when no one can or cares to
get around to look at it.
The utility of food patches planted and left unharvested for
quail and other wildlife varies with the circumstances. Food
patches have been known to work and they have been known
not to. Our present opinion is that food patches on non-agri-

411
Fig. 24. Bob-whites forced by necessity may even learn to shear away corn husks
to get at the ears.
cultural land should be of fair size (up to a half acre or an acre)
and should be long and somewhat narrow rather than square
in shape. The sizes we recommend are larger than those usually
planted, but they should be large enough to be attractive to
quail as well as large enough to feed the rabbit, rodent and
miscellaneous competitors which are usually present.
For use in food patches we have found sorghum, kaffir corn,
buckwheat, and soybeans fairly satisfactory but not outstand-
ingly so. A considerable amount of interesting experimentation
is in progress in a number of states, and there is a growing liter-
ature upon the subject, but anything more than very tentative
conclusions would be premature at this time.
In simplest practice, assuming that there were no valid ob-
jections, farmers might well leave unplowed until spring the
sides of stubble fields grown up to pigeon grass and lesser rag-
weed, and so give the birds a chance to feed on the seeds during
the winter. During deep-snow crises, grain-bearing manure
might be scattered on fields nearest brushy borders instead of
far out toward the centers. If the farmer's habit is to haul his
shocked corn in from the fields about as he needs it for winter
stock feeding, he could with practically no trouble leave for the
last those shocks which were situated near quail coverts. He
might not even be inconvenienced or out of pocket if he deliber-
ately left out a few shocks for the quail until winter was safely
over.
Where deep and lasting snow is expected each winter, each

412
bob-white covey should have access to partly open corn shocks
or to a number of sources of substantial foods equally depend-
able throughout any ice or snow storms within probability.
Shocks properly constructed furnish emergency refuge as well
as food, and if the food becomes exhausted or too difficult of
access, additional grain may be thrown inside now and then.
This should be emphasized: Any method of feeding which
demands daily human attention or forces the birds to feed in
one place is intrinsically unsound. The more automatically the
food remains available and the more alternative courses of
action the quail have in the event of visitations by predators,
the more security may be assured.
Although the food in a given locality may be roughly ade-
quate during ordinary winters, ice storms and deep snows may
precipitate wildlife crises that call for large scale action. Broad-
casting of grain on top of the sleet or snow is an excellent emer-
gency measure but not one to be recommended for steady feed-
ing because of its wastefulness and because of the irregularity
with which food may be put out. On the whole, it is much easier
to induce people to get out on occasion with bags of grain than
to inculcate into them the idea of planned management. Repeat-
ed radio broadcasts and newspaper releases after blizzards may
be notably effective in arousing interest; and, wasteful both of
food and of energy as much emergency feeding may be, by this
means great numbers of birds may often be saved from starva-
tion.
MANAGEMENT OF COVER
Bob-white winter cover may be anything that affords the
birds concealment or refuge from danger. It is usually living
vegetation of brushy types or dry vegetation of herbaceous
types. To be effective it must be situated within convenient
distance of roosting or feeding grounds (fig. 25).
A given acreage of cover may serve the maximum number
of quail if it is distributed over a farm in strips or patches rather
than centralized in a solid block such as a woodlot. Occasional
thickets and fencerow brush distributed here and there may
constitute adequate escape cover. Cover is needed not only dur-
ing the winter but during the nesting season as well.
While we are mainly concerned with winter cover in this
writing, it may be significant from the standpoint of manage-
ment to quote the following from a popular bulletin [Errington
(22)]:
"Superior nesting cover is bluegrass or Junegrass (Poa) of
the preceding years growth along roadsides, wide fencerows,
and in meadows and orchards. Quail beginning to lay eggs
about the first of May prefer to nest in such locations, but if all

413
Fig. 25. Food and cover, to be of greatest utility for bob-white, should be conveni-
ently situated with respect to each other.
of the places naturally suited to them have been spoiled by
burning, mowing, or pasturing they are forced to take what
cover they can get. Nests made in scanty cover or in weedy low
spots are apt to be broken up or flooded. While the quail raise
only one brood a season, birds unsuccessful in hatching out
their clutches early will commonly renest in the cover that is
most inviting at the time, usually clover and alfalfa fields which
are almost sure to be mowed over before incubation has been
completed. Hence the destruction of nests [and adults and
young, as well] by hay mowing would be to some extent less-
ened if the birds had attractive nesting territory elsewhere than
in the fields."
Much of the cover deficiency in established "quail country"
may be directly and indirectly attributable to agricultural
practices and to the widespread feeling among landholders that
all wild vegetation has to be kept "cleaned up," irrespective of
what it is or where it is. Whatever may be the alleged advan-
tages of so-called "clean farming," it should never be over-
looked that over-zealous adherence to the doctrine may lead to
the irreparable ruin of much land through erosion. "Clean
farming" carried on to an extreme on soils of certain types or on
lands of steep gradients may mean nothing less than commun-
ity suicide.
From the standpoint of the bob-white, the restoration of
adequate cover may often be accomplished merely by giving
wild vegetation a chance to grow up at strategic places. Wild
414

100000
ņ
$
RECOMMENDED GAME COVER PLANTINGS ADAPTED TO EROSION CONTROL
Prepared by Logan J. Bennett for
THE IOWA FISH AND GAME COMMISSION AND THE IOWA STATE PLANNING BOARD
SMALL SECTION
SHOWING TYPICAL
GROUP PLANTINGS
D
JBYJDO
EXTENT
MARGINAL
35 YARDS
OF
AREA
EROSION-CONTROL
GULLY
D
alimvini
TTGGU
Mad Maria
all withi
YOS.-D
FENCE?
GROUP
GROUP A
GROUP B
GROUP C
GROUP D
GROUP E
OTHER
PLANTS
PLANT
Black Locust
Willow
*
Wild Plum
Sumac
Prickly Ash
Hazel Brush
Coral Berry
Raspberry
Roses
Wild Plum
Hazel Brush
Prickly Ash
Wild Grape
Plants
Sq. Yd.
1
1
4
3
4
10
20
7
7
4
10
4
|
MARGINAL AREA IN YARDS*
8 | 12 | 15 | 20 | 25
30 | 35
Entire Gully Plus One Yard Over Brink
Entire Gully Plus One Yard Over Brink
78
7
8
7
7 1
7 8
222 N
2 |
| 2
2
2
1
1
1
3
3
3
3
| 3
3
3
|
2
2
I
4
4
4
4
4
4
+
| 22
2
2
enen en in
5
5
5
5
56
enjen
5
5
6 |
6
6
6
4
4
4
6
6
6
6
6
| 7
7
∞∞∞
8
8
8
8
8
8
8❘ 10
10
10
| Add. Width Strip in Yards Shown Above
Plant cuttings along fence row around gully.
One plant placed every four feet.
Plant in clumps and in odd corners of gully-
control plot. Six plants to the clump.
Malta +
·
Elderberry
Marginal area is the distance from the brink of gully to fence that will be
put in surrounding gully.
NOTE: To produce an ideal game covert one strip of plants (one species)
from each of the above groups should be planted. They should be planted in the
order given from the gully out. The above figures are approximate and the super-
visor in charge of planting will use his own discretion if a certain group of plants
is not available.
Fig. 26.




415
vegetation may be supplemented by plantings (preferably of
native species) if the land owner is so disposed and financially
able.
Commonly, we have not been advocating very strongly the
intensive planting of trees and shrubs for quail cover except in
connection with erosion control projects (see fig. 26). Planting
on any considerable scale may involve a greater expenditure of
time or money than most landholders can afford for the sake of
wildlife alone. But the fencing off from stock of brushy and
grassy patches here and there may not be too much trouble, nor
may the erection of a few brush piles where they may do the
most good.
Brush piles at the edges of pastured woodlots or open tim-
ber may add a great deal to the habitability of the land for quail,
and few indeed are the cover combinations that may not be
bettered by the judicious placing of brush piles. Limbs which
have fallen during windstorms or have been trimmed from trees
cut for firewood make good material for piling. If the land-
owner cares to, he may prepare cover in over-grazed woodlots
or those lacking underbrush by felling trees for seasoning, lop-
ping off the lower limbs, and stacking them about the top.
The intelligent management of bob-white cover may be dif-
ficult or easy, according to the circumstances. On some farms.
the prospect of encouraging bob-whites may be so lacking in
promise that to try anything would scarcely be worth the
trouble involved, with that object alone in mind. On other
farms, it is simply less trouble to have quail cover than not to
have it.
Intensely cultivated farm lands tend to have too little cover
for bob-white populations of high density; wild or reverted
lands tend to have too much. Lands under moderate cultiva-
tion, then, may furnish more nearly optimum environment for
the species. Quality and dispersion constitute the main criteria
of the effectiveness of cover in bob-white range.
There seems to be no definable minimum or maximum of
cover for a habitable range. Good "quail country"-as well as
that which is obviously unsuitable is usually recognizable as
such by experienced observers, but at present we are quite
unable to state just where habitability begins or where it leaves.
off. We are sure that a marginal territory is habitable when the
birds have demonstrated that it is. So far as expressing habita-
bility of an environment as an exact formula is concerned, that
may be looked forward to as a possible accomplishment of the
future.
In practice, a varying amount of cover management may
often be interwoven into farm routine to the advantage not only
of the bob-whites but of the farm as well. Wild plant growth
does not necessarily represent a thing of evil simply because it
416
is wild. Wild brush on a given farm is frequently looked upon
as evidence of a landholder's shiftlessness, but its presence may
actually denote instead a superior understanding and an ad-
vanced attitude toward the land.

Not always is there real justification for the chopping away
of briars or grape vines from fencerows or the clearing of odd
corners. Not always is there justification for the destruction of
brush along highways where drifting snow does not constitute
an important problem and where the visibility is not obstructed
seriously. Unless such cleaning up has an integral role in the
control of dangerous weeds or insect pests, or otherwise serves
some useful purpose, much of it could well be left undone.
There should be places on practically every farm where wild
vegetation could be left unmolested or encouraged for the sake
of wild species dependent upon it for habitats, and with no
actual detriment to the farm nor inconvenience to the land-
holder. The concealment of unsightly places such as dumps,
gravel pits, rock piles, etc., by plant growths dense enough to
furnish cover for wildlife could well be worked for.
Burning, when necessary, should be done with the utmost
discretion and certainly not in the nesting season of the
birds. Burning may be a valuable means of stimulating later
plant growth [Stoddard (70, pp. 401-410), (72)], but it is im-
mediately destructive of wildlife environment and care should
be taken to prevent fire from sweeping solid areas bare of food
and of cover. While blind and habitual burning of marshes and
wild lands should be discouraged, it should be borne in mind
that fire has its legitimate uses as well as its abuses.
Perhaps cover management on a given farm is only a matter
of withdrawal of cattle from wooded hillsides unprofitable for
pasturage in the first place. Cover management does not require
that vigorous growths of native vegetation be dug out and re-
placed by imported shrubbery of no superior merit but which
costs money. Cover management need not necessarily mean
any revolutionary changes in land use; it may mean simply bet-
ter use of the land for the purposes for which the land may be
best adapted.
PREDATOR CONTROL
It is true that bob-white winter populations under wild con-
ditions frequently suffer severe losses from predators. The toll
from predators, however, may be separated for analysis into a
number of distinct types, and these types should be consid-
ered separately if a true understanding of predation is to be
gained.
B
Of these types, one may be characterized by the slow rate of
loss which probably continues over the whole year. We have

417
1
succeeded in measuring losses of this type only for the winter
months, for which season, according to present data, the losses
have rarely exceeded a rate of 6 percent of the population per
90 days for observational areas of any size. This is a loss seem-
ingly suffered by all adult bob-white populations, regardless of
how strongly they may be established in their environment.
We look upon this loss as unavoidable and immaterial, since it
seems to correspond rather closely to the loss which one might
expect from age and accident alone if there were no predators.
Winter mortality from predation of another type becomes
conspicuous when large numbers of birds are weakened by
starvation, wounds, or possibly by disease, and hence are
unable to escape enemies which ordinarily would have difficulty
in capturing them. Starving birds so weak as to be caught
easily by predators usually die anyway in a day or two, and the
mortality following shot wounds and sickness is anything but
low. Then, too, sub-zero cold snaps kill off the weak birds on a
wholesale scale, whatever may be the cause of their weakness.
We have been trying to learn whether harassment of starv-
ing birds, as by hawks, really results in any increased loss, but
so far we do not know. On the basis of observations dealing
with a goodly number of starving coveys, we would judge that
starvation emergencies are aggravated by attacks of predators
but not necessarily enough to make much difference in final
survival.
Harassment appears to be followed by most severe conse-
quences when birds are forced to concentrate about a few
sources of food, localized, as for example, at artificial feeding
stations. This seems especially true when the attending preda-
tors are Cooper's hawks. Even under such circumstances, it is
difficult to evaluate with accuracy the role of harassment or of
local over-population in bringing about the conspicuous mor-
tality when observed.
The third and most important type of predation on winter-
ing bob-whites has been discussed in detail throughout this bul-
letin. It represents the pressure of enemies upon that part of
the quail population which is vulnerable because of its inse-
curity of position, or, in other words, the pressure upon what is
left of the annual surplus by winter. Birds in excess of the
carrying capacity of the land may be in good physical condition
but they lose out nevertheless through over-crowded or inferior
environment. As long as there are more birds than the winter
environment can accommodate, something happens to the extra
ones, and, so far as we have been able to determine, regardless
of the kinds and numbers of predators ordinarily present.
We admittedly know little enough about predation upon
summer adults, but the evidence seems to indicate light losses
from predation except in the earlier part of the season. A certain
418
rise in vulnerability seems to correspond to the period when
the birds are most occupied with mating and nesting, as has
been shown by contemporaneous food habits studies on foxes
[Errington (30)], great horned owls (unpublished) and some
other predators.
A fifth type of predation-that upon eggs and young-has
not been satisfactorily studied in the North from the standpoint
of its actual effect upon quail populations. To Stoddard (70)
may be credited the best work on this phase of predation that
has to our knowledge been done on the bob-white.

So far as management of the northern bob-white is con-
cerned, aggressive control of winter predators seems to be
futile, except perhaps under unusual circumstances. Grange
and McAtee (37 p. 45) state: "When control is undertaken, in-
flux of predaceous birds from other areas soon fill the vacancies.
The yearly toll taken by predators on many game farms is
almost constant, indicating that no real progress has been made
even where wholesale control is attempted." Perhaps Cooper's
hawks which habitually frequent quail feeding stations may
be eliminated to advantage, but our data on this point are not
too good. On the whole, heavy bob-white winter mortality from
predation appears not so much a matter of few predators or
many predators, but of how many birds are either weak them-
selves or dangerously exposed through weakness or inadequacy
of their environment.
It is conceivable that a reasonable control of the chief nest-
ing enemies of the bob-white, under given conditions, might be
worth while from the standpoint of management. Stoddard
(70, pp. 415-437) considers such predator control important in
the management of the bob-white in southern states. His find-
ings are doubtless applicable in part to northern states, though
to what extent is not apparent. Our own studies, conducted on
lands largely trapped annually for fur-bearers during the cold
weather months, have shown little need for the taking of ag-
gressive measures against egg-eating species in north-central
states.
Sil
We have reason to believe that control of nesting enemies
is no substitute for suitable nesting cover, but, if circumstances.
seem to demand that predatory species be reduced, control
measures should first be undertaken against house cats and
stray dogs and possibly forms which may be overly abundant,
such as ground squirrels ("gophers") and crows. Any taking of
fur-bearing predators as foxes, skunks, minks, raccoons and
others should be confined, as much as possible, to the winter
months when the pelts are prime and salable; in this way a re-
grettable wastage may be eliminated, and management may be
made to pay cash dividends, sometimes very substantial.
Let it be made clear that predator control is nothing that

419
lends itself to rule-of-thumb formulae. It may be desirable, in-
consequential, or highly undesirable-all according to the cir-
cumstances and the species subject to control. In general, it
is best to bear lightly upon native species, and particularly
those which have low reproductive rates or are losing ground
numerically, even though as yet they may not be actually rare.
Predator control as a management measure is consistently
over-rated by the public, not only as it concerns quail but
practically every game or "song bird" species. Most people
consider it a privilege if not a duty to kill any predatory
creature on sight. This attitude is not in keeping with the
findings of biological science, nor can it be said to signify the
highest aesthetic appreciation of the out-of-doors and what it
represents.
It is high time that the public recognized its responsibilities.
in the safeguarding of predatory species just as much as any
other integral part of the out-of-doors or any other natural
resource. The writings of McAtee (55, 57, 59) and Leopold (47,
50, 52) bring this out with particular force. Without attempt-
ing discussion of the little known but complex role of predators
in nature, we may say that it ill behooves us to destroy any por-
tion of our heritage, of which we have such scant knowledge.
Research findings hint more and more that most native preda-
tory species which have been the object of study could be made
to fit very advantageously into a sound system of land use.
Whether popular indifference and prejudice will ever permit.
such biotic possibilities to be fully or even partially realized is
problematical.
On the whole, the soundest way to protect a given species-
wild or domesticated-from predators is by making it difficult
for the predators to prey upon it. In the case of wintering bob-
whites, reduction of pressure from one enemy apparently is
followed by a compensatory increase of pressure from others as
long as the birds are vulnerable from any cause; how much this
may be true for summer adults and for eggs and young we do
not know.
Stoddard's work on bob-white nesting indicates that control
of nest-destroying enemies may be followed by higher fall pop-
ulation levels. Errington's nesting and population recovery
studies in Wisconsin (23, 26) seem to suggest that ordinary
nest destruction may not have such a pronounced effect in de-
termining populations.12
We suspect, nevertheless, that control of nesting enemies
may be attended by greater increase of young during the breed-
ing season in northern states. This would mean a larger fall
surplus of birds available for sporting purposes. Any increase
12. Wholesale nesting losses, as from drouth [Errington (29)] or from ants
[Stoddard (70), (71)], doubtless belong in a different category of significance.
420
thus to be gained would probably be lost in considerable part,
though, unless the shooting were done comparatively early in
the season, before any top-heavy surpluses had been exposed
too long in environment of shrinking carrying capacity.
MANAGEMENT OF SHOOTING
The commonly observed failure of bob-whites to increase.
under protection beyond a certain level is plainly due in most
observed cases to the inability of the environment to accommo-
date any more than that level. The comparatively rapid re-
covery of quail populations often to be observed after heavy
losses from shooting, starvation, or natural cataclysms seems
likewise correlated with the carrying capacity of the environ-
ment.

Sportsmen, noting these two population phenomena in a
general way, have advanced their hypothesis of inbreeding. By
this they have assumed that if quail coveys are not scattered
as by shooting, mating will occur within family groups and to
the detriment of the species. According to this hypothesis.
unshot, inbred populations all but stop breeding and so remain
nearly stationary until scattering from shooting breaks up un-
natural alliances; with normal mating restored, a healthful ac-
celeration of breeding builds populations up again.
This hypothesis lends itself conveniently as a talking point
for those opposed to totally closed seasons on bob-white, and
as such it has been avidly propagandized. Others have simply
misinterpreted the more or less fragmentary evidence which
has come to their eyes, sometimes in a perfectly logical way,
or have not recognized the fatal criticisms to which the
hypothesis is subject (for discussions, see Stoddard (70, pp.
494-497); Leopold (46, pp. 54-55).¹³
13
-
It is doubtless mainly true that the rate of increase per
breeding pair of bob-whites surviving an intensive shooting
season is higher than for unshot populations (assuming that
the birds have recovered from any shot wounds, etc.); but the
same thing seems equally true for the survivors of a drastic
starvation emergency. It does not follow that quail need to be
shot or starved to breed properly. Shooting, starvation, or any-
thing else of temporary emergency nature that kills large num-
13. The principal sources of biological evidence against harmful inbreeding of
bob-whites in the wild may be briefly listed: (1) Existence of the species in practically
unchanged form since at least Pleistocene time;
(2) The evident correlation of weight averages with geographic distribution,
irrespective of shot or unshot localities;
(3) The continual splitting up and recombination of coveys which occurs incidental
to rising population densities, and the movements of individuals for considerable dis-
tances in response to seasonal and other natural stimuli;
(4) The lack of evidence that inbreeding per se would be detrimental to stock of
sound genetic composition, even under conditions which may be considerably more
favorable to inbreeding than we can conceive of in nature on any important scale.
421
bers of birds simply serves to lessen population pressure and
so accelerates recovery of the surviving population, always
provided that reduction of numbers has not proceeded too far.
Nor does it follow that the accelerated rate of increase will be
enough to compensate in one breeding season for heavy losses
suffered before.
It is plain enough that bob-white populations do not in-
crease at rates approaching their breeding potential nor do they
increase at rates at all uniform. One may get out paper and
pencil and start figuring that so many pairs will average so
many young per pair which will give a population of so many
birds by fall, but the resulting figures are likely to be extremely
misleading.
There is some evidence that we may ultimately be able to
calculate bob-white population recovery with fair accuracy, if
we know certain essential facts. To do this, we need accurate
year to year population records on specific areas and evidence
as to carrying capacity of the same areas. We need also some
way of evaluating the effects of drouth [Leopold and Ball (53);
Errington (29)], disease, cycles [Leopold (48)] and similar
obscure but perhaps very powerful influences on reproduction.
It is entirely possible that we could well carry on some studies
of the potential fertility of the bob-white as Severtzoff (69) has
done for certain Old World forms.
Data of good quality on population recovery come in with
extreme slowness, but those which we have indicate that the
rate of recovery varies inversely with the density of the popula-
tion in relation to the winter carrying capacity, and possibly the
fall carrying capacity, of the environment. In other words, a
heavy population in strong environment and a low population
in weak environment both show but limited increase after the
breeding season; whereas a low population in a strong environ-
ment stands a better chance of showing decided increase from
seed stock.
At one extreme, we may find well situated remnants of sub-
stantial populations recovering from cataclysms at a rate of
five or six or perhaps more young per pair. At the other ex-
treme, the increase may amount to less than one bird per pair
for populations near environmental carrying capacity [Erring-
ton (26)].
Of all the areas which we have studied, the one at Prairie
du Sac, Wis., has contributed the most reliable data on rate of
increase of populations during the breeding season. These data
are singularly reliable because of the large size of the area (5
square miles, or enough to reduce materially the likelihood of
much influx or egress during the summer months) and because
of the excellent quality of the data secured over a period of
years.
422
The data from this area lend themselves well to tabulation
(table 75) and may profitably be studied with care. Since the
CWA debrushing for 1933-34 came after the fall census figures
were quite complete and since the effects of the debrushing on
the cover were largely lost during the 1934 growing season, it
is probable that the summer and fall environment as a whole
has remained much the same for the period of observation.
TABLE 75. POPULATION RECOVERY ON 5 SQUARE MILES, EAST OF
PRAIRIE DU SAC, WISCONSIN, 1929-34.
December population

Year
1929
1930
1931
1932
1933
1934
1935
April population
Birds
22?*
112
236
290
339
288
196
Bird: acres)
1:145 (?) A.
1:28.5 A.
|
1:13.6 A.
1:11 A.
1:9.4 A.
1:11.1 A.
1:16.3 A.
Birds
121
257
400
406
433
411
416***
(Bird: acres)
1:26.4 A.
| 1:12.5 A.
1:8 A.
1:7.9 A.
1:7.4 A.
1:7.8 A.
1:7.7 A.
Rate of recovery
from seed stock
during breeding
season
450%**
129%
69%
40%
28%
43%
112%

* and **
During the winter of 1928-29, Gastrow (letter, July 12, 1935) observed the
shrinkage of a covey of 30 to about 6, from late December to spring. This was the only
covey regularly noted and apparently represented the combined populations of territories
No. 5 and No. 13. Since the population of these territories has averaged 28% of the area
population, pro-rata calculations would place the number surviving on the area in the
vicinity of 22 birds. We think that this number is not far from the number that actually
survived.
*** The initial figures for the fall of 1935 represent the average for November rather
than December and hence may be somewhat high in comparison with the counts for
previous years. The population suffered a very slight reduction from shooting in October,
however, which may tend to offset any error in this direction.
These data are of particular interest and of application to
management, in that they give some inkling as to what may be
the effect of over-shooting, and as to what population levels
may be most advantageously maintained for sporting purposes.
Unless over-shooting is truly drastic, even if continued it
probably never would lead to the progressive extermination of
the bob-white in environment at all favorable to the species.
The chief effect of moderate though continued over-shooting
would probably be to hold populations at some comparatively
unsatisfactory level distinctly below the full carrying capacity
of the land. We suspect that many quail populations in states
having general open seasons are in actuality over-shot and
hence may be looked upon more or less as under-populations
most of the time-not necessarily insecure under-populations,
however.
For that matter, peak populations need not without excep-
tion be the ultimate goal of management for sport. Populations
of a bird per acre may not be practicable to manage even in
strong environment nor even a bird per 2 acres. It may be that
a bird per 4 acres may be the optimum level from all stand-
points, though the environment may be capable of accommo-
dating twice that population.
423
Let us speculate that a fall population goal of 433 birds was
arbitrarily set for the Prairie du Sac area before any shooting
would be permitted. If the continuance of this initial fall level
were to be insured, the population probably could not be reduc-
ed much below the 339 seed stock level from which the increase
up to 433 birds was known to have come. This would permit a
take of but 94 birds or 22 percent of the population, including
dead birds unrecovered and those lost from crippling. The loss
of birds incidental to shooting sometimes amounts to 50 percent
of those hit [Errington and Bennett (33); Errington and
Hamerstrom (35)], but such a high percentage of loss is com-
monly avoidable through the use of retrieving dogs and the
exercise of more care.
On the other hand, if shooting might begin on a fall popula-
tion of 257 birds, the stand could be cut down to 112 birds or
thereabouts, and still leave sufficient seed stock reasonably to
insure recovery up to about the same level by the next autumn.
The human toll could then be in the vicinity of 145 birds or 56
percent of the fall population annually, contrasted with but 94
birds or 22 percent at the higher level.
Our data on population recovery are admittedly scant, and
any conclusions drawn from them should be distinctly tenta-
tive. We do not know if population recovery may ever be work-
ed out by means of formula, even in years when the season's
hatch may be neither extraordinarily good nor bad. We need
vastly more accurate data for specific areas over long periods
of time.
Studies on experimentally shot game management areas in
southern Iowa during the fall and winter of 1933-34 indicate
that it is biologically sound to take by shooting that portion of
the population which represents the surplus from breeding or
that portion in excess of the winter carrying capacity of the
land [Errington and Hamerstrom (35)]. In 1933, as measured,
this surplus for the Iowa areas under observation seemed to
average about 30 percent at the beginning of the winter, judging
from the losses suffered by the unshot areas used as checks.
This estimate could doubtless be placed higher-perhaps at
40 percent for late fall populations.
The effect of shooting on over-populations may be some-
what more severe than predation, even though only the equiva-
lent of the vulnerable surplus may be shot. Nevertheless, it is
certainly safe to shoot the surplus, whatever that may be for a
given area. How much more than the vulnerable surplus may
safely be shot we can only guess, in the absence of experimental
data on what toll different population levels may actually stand
in environments of different carrying capacities.
The administrative difficulties of management of shooting
424
are tremendous, and on this subject we have very little to con-
tribute. We doubt if quail shooting can be regulated with any
great precision. Perhaps the most one can hope for is to keep
the shooting, when it is done, under reasonable control. For
practical purposes that may be all that is needed, especially if a
system could be evolved which would function more or less
automatically.
When quail need increased protection-as after cataclysmic
emergencies such as drouths, killing winters, etc.-it is to the
hunter's ultimate interest to see that they get it, whether that
means suspension of his sport for a year or two or not. Total
closure of the shooting season may at times have its place in
bob-white management, but there are limits as to what should
be expected of it. Total closure should be regarded as an emer-
gency measure, but it constitutes no substitute for the funda-
mental environmental requirements of the species. All the legal
restrictions which can be laid down cannot bring about heavy
populations of birds on lands having carrying capacities rang-
ing from a bird per 20 to a bird per 40 acres.
A bird per 40 acres population may have a biological sur-
plus, in the sense that we use the term, namely, to denote that
portion of the population which is in excess of the carrying
capacity of the land and which is doomed to be lost anyway.
Nevertheless, the surplus of such a population or even the
entire population itself would hardly make a satisfactory shoot-
ing, and it would probably be best not to consider shootable
any populations under a bird per 10 acres, and preferably not
under a bird per 6 acres.
G
Shooting seasons should come soon after the fall shrinkage
of cover, for at this time top-heavy surpluses may be utilized
for sport instead of being left to their natural fate. Of course,
if the object of management is not to provide shooting, shoot-
ing doesn't have to be done. Shooting is not a biological neces-
sity; neither is it a practice necessarily detrimental to the
species, if wisely regulated.
Whether shooting is to endure as a sport depends to no
small extent upon its followers. Whether it endures may be
contingent upon the progress which its followers are able to
make in the elimination of the social and biological abuses
which have hitherto attended it. These abuses have received
much editorial space and are familiar to practically everyone
conversant with the subject of hunting. We shall not delineate
them here.
POPULATION ESTIMATES
The measurement of existing quail populations is of great
practical value in the management of the species. This is true
whether an inventory of the wild stock is desired as a basis of
425
recommendations for a shooting season, or whether the purpose
of the measurement may be to evaluate management progress
or the havoc of a natural emergency.
Whenever possible, census methods of proved reliability,
such as those discussed earlier in this bulletin, should be used
in all studies demanding accurate counts. Census-taking, how-
ever, is laborious and slow at best. It is not adapted to hasty
surveys of large areas, though it should be used locally to check
the reliability of approximations derived from less exact but
often more practical techniques.
Kendeigh (43) has used the annual Bird Lore Christmas
censuses as a basis for calculations of wintering bob-white pop-
ulations on a state-wide scale. Figures so derived seem to pre-
sent a remarkably clear picture of the yearly fluctuations in
abundance of the bob-white as well as of other species, though
they depict general rather than local situations. The Bird Lore
census is conducted each year in somewhat the same localities
by somewhat the same group of observers. It is sponsored by.
and information and data may be obtained from, the National
Association of Audubon Societies.
·
In the course of the quail studies which we conducted on a
rather extensive scale in southern Iowa in the fall and winter
of 1933-34, we worked out a fairly satisfactory technique of
determining approximate populations by marking on a map the
territories which "sign" (droppings, dustbaths, feathers, tracks,
etc.) showed to be occupied. The effectiveness of the technique
is largely dependent upon the skill of the observer in "reading
sign" and in recognizing the probable dimensions of the indi-
vidual covey ranges.
Another technique which served well in very hurried sur-
veys was the estimation of probable covey territories from the
road, checked by careful examination of representative environ-
ment now and then, just to make sure that the estimated terri-
tories were generally being occupied. In this sort of work, a
good dog may be used very advantageously, especially when
there is no snow on the ground.
On three areas where the pressure of time during the fall
of 1933 did not allow even calculations of territory on the basis
of sign, Errington made some experimental estimates from the
road only, later checking them by actual census work. Of 17
covey territories estimated without actual examination of the
land, 16 proved to have been correct [Errington and Hamer-
strom (35)]. The checking was entirely independent of the
original estimates.
Leopold (48, pp. 378-380) suggests a technique for making
habitability tallies of bob-white range from trains or motor
cars. These tallies may be made to best advantage if the time.
of year is that of the critical season and if the range is open
426
enough to permit identification of food and cover types for at
least one ordinary covey cruising radius from each point of
observation, or station.
The successful application of the various techniques for
estimating quail populations is dependent not only upon the
ability of an observer to recognize habitable quail environment
when he sees it, but also upon the degree to which the environ-
ment is filled to capacity. These techniques are most useful in
late fall or early winter checkups, but they have distinct draw-
backs as well as advantages.
In the first place, they cannot be substituted for census tech-
niques if census accuracy is required. Commonly, the average
size of a bob-white covey is 15 birds, but obviously hard and
fast statements as to covey sizes should not be regarded too
seriously, since coveys vary all the way from 3 or 4 birds up
to 30 or even more. One may flush a given covey as 20 birds one
day or as two coveys of 10 each the next. The resulting coveys
of 10 may be either widely separated or adjacent, or they may
split off from a compact group in flight. Even so, 15 birds is
not far from the average number in a fall covey year after year.
If, for any reason, quail populations are decidedly below the
carrying capacity of the land over wide areas, the efficacy of
estimating techniques is reduced. The 1934 drouth in southern
Iowa, for example, precluded the use of any technique which
was not at least checked by actual censuses; the birds were
simply not present in their usual fall numbers [Errington (29)].
Poaching or unrecorded shooting also may upset population
estimates unchecked by field censuses. Populations incomplete-
ly recovered from previous winter-killing can hardly be esti-
mated accurately on the basis of the number of birds which
ought to be there, though the observer be an experienced judge
of territory.
In short, population estimates under conditions favorable
to their use may be fairly accurate and quite valuable from the
standpoint of administration, but they should always be check-
ed by some careful census work. If the numerical status of bob-
white populations is known to be atypical, it may be best not to
place any confidence in estimates.
At times, bob-white fall populations may be unusually high,
in which event an over-populated condition may often be recog-
nized by conspicuous evidence of predation and mortality from
other causes. Granted that the losses are not due to some
serious natural emergency, or directly or indirectly to the ac-
tivities of man, an accelerated fall mortality rate might be wel-
comed as evidence of a strong population of birds and a sub-
stantial surplus.
Reports of hunters and farmers as to numbers of birds have
proved almost uniformly to be too inaccurate to be accepted in
•
427
▼
lieu of censuses. For purposes of accuracy, the opinion of a
farmer who has lived on a place all his life or of a hunter who
has covered it for years may frequently be less reliable than a
quick size-up of the food, cover and territory relations by one
skilled in such work.
Adeptness in evaluating quail range is not anything that
requires an academic degree or any formal training, though it
does require the scientific attitude of striving to find out only
what is true, regardless of what that may be. An observer
should be sufficiently familiar with the species so that he will
not jump at the conclusion that, because he flushed a covey of
quail on the west side of the corn field one day and the same or
a different number on the east side of the field the next day,
the two coveys must be two different ones. An observer should
also be able to count about 20 birds in a covey of 20 instead of
guessing that there were 30 or 40.
Almost anyone can learn to census or to estimate quail pop-
ulations if he has intelligence and the right attitude. The atti-
tude, to our way of thinking, is most important, whatever may
be an observer's other qualifications. Unless he can approach
a problem objectively, with nothing to prove either way, his
statements will always be legitimately subject to discount.
Stoddard (letter, Aug. 27, 1935) suggests a technique we
have never tried which sounds very workable. He writes: "I
personally use the morning whistling method all through the
fall and winter months on doubtful quail territory. . . . prev-
ious to lease or purchase, or where the quail population on a
preserve is in doubt, dogs under suspicion, etc. Coveys either
whistle from the roost for a few minutes or may be stimulated
to do so by a skillful whistler, just at the moment of clear light,
especially on fine, quiet and clear mornings. Have frequently
roughly located the roosting locations of six to eight coveys
from one location on one morning." He considers the method
much more reliable in ascertaining the number of coveys than
covering the ground once with bird dogs, particularly when the
coveys are moving to a limited extent and the conditions for
scenting are bad. He suggests for northern studies that "
early morning calling from the roost might be very useful in
October and November, before the snows come."
EXPERIMENTATION ON THE LAND
In our bob-white investigations, we have relied primarily
upon intensive field observational techniques. We are in
agreement with the scientific school which holds that research
tends to become more and more a matter of experimentation as
progress is made on a specific problem, but it has been our
philosophy that for these studies, at least, a substantial founda-
tion of preliminary observational facts needed to be laid first.
428
A fully balanced program calls for continuous checking of
observation by experimentation and vice versa. It also calls
for repeated critical analyses and interpretation of existing
reliable data, irrespective of conclusions which may have been
arrived at, or published along the way.
We feel that, with respect to observational data and critical
analyses, our bob-white researches are just beginning to bear
tangible fruit. We should judge that our experimental data are
much weaker than our observational data, even in elementals,
but it cannot be truthfully said that we have no start at all in
the experimental stage.
For that matter, our observational data to a considerable
extent may correctly be regarded as having experimental
values. As a whole, they depict with fair accuracy the response
of populations to environmental changes as well as they depict
the behavior of birds under comparatively stable conditions.
They apply to a vast number of situations, which, if not actually
planned in advance by the investigators, often had the virtue of
being excellent accidental substitutes for situations of the sort
that would have been induced in an experimental program. In-
deed, a great many observational data may be as truly experi-
mental in nature as many of those obtained as a result of delib-
erate manipulation.
Why, for example, should the accurate recording of the
effect of environmental changes on a wintering quail population
in a given observational area have so much less value if the
changes were made by a farmer, undirected and of his own
accord, rather than by the investigator himself? Granted that
many of the environmental changes-favorable as well as un-
favorable to quail-brought about in connection with agricul-
tural practices may not have been planned or even suspected in
advance by the investigator, carefully kept records of salient
biotic adjustments, combined with data for years previous to
and years after the changes had taken place, may nevertheless
have substantial utility.
Then, too, we have found that an investigator's control of
many of the natural factors affecting wild bob-whites may be so
tenuous under even the best of experimental conditions that he
cannot rely upon getting experimental data on all phases of life
history that he may be studying. Wildlife research often re-
solves itself largely into getting what apparently significant
data can be got, of whatever kinds, wherever, whenever, and
however they may come to hand.
The salient advantages of a predominantly observational
technique in our quail studies have lain in the comparative ease
with which voluminous data under a variety of conditions have
been secured. The sheer volume of the observational data on
thousands of wintering bob-whites should go a long way
429
toward compensaung for what has not been accomplished by
strictly experimental means.
Experimentation on the land, however, is of the utmost
necessity in the testing of techniques for bob-white manage-
ment or the management of any other wild life species. With
regard to this type of experimentation, we are still in a begin-
ning stage, and the ultimate possibilities of trying things out on
the land seem to be endless. But to follow a well rounded ex-
perimental program would require funds, time, man power and
some control of land beyond that which has so far been avail-
able to us.
Mention has already been made of the 1933 experimental
shooting program conducted by the Iowa Fish and Game Com-
mission on 14 official game management areas [Schuenke (68)].
One of the objectives of the shooting was to determine experi-
mentally whether the removal of surpluses by shooting in late
fall and early winter would lower the vulnerability to predation
of the populations wintering on the areas. The experimental
shooting related to more than 25,000 acres in 14 areas, of which
10 areas were productive of more or less reliable data. The
wintering loss on the 10 shot areas collectively amounted to
but 10.3 percent of the population surviving the shooting, con-
trasted with a collective loss of 28.3 percent on the four similar
but unshot areas used as checks [Errington and Hamerstrom
(35)].
As a rule, the Iowa program of signing up private farm lands
in state game management areas has been of unquestionable
effectiveness in the protection of game from poaching. Getting
real environmental improvement accomplished by the land-
holders on these areas, however, has been a tremendous task.
With some encouraging exceptions, farm practices on private
lands under observation between 1932 and 1935 have continued
essentially unchanged as concerns wildlife habitats, agreements
to the contrary notwithstanding; hence private lands have not
proven to be very productive of data demonstrating what can
be expected of practiced management.
We have studied personally five areas which have yielded
reliable experimental data on bob-white management. Of these
five areas, four represented public land to some degree made
available to us for experiments; and the fifth, private land upon
which environmental manipulations were conducted at the ex-
pense and under the direction of the Iowa Fish and Game Com-
mission. On these areas, changes were actually made in
environmental relationships, and the apparent reactions of the
quail populations to the changes were noted in greater or less
detail. The data resulting from these experiments may be sum-
marized according to areas.
Experimental Area I, including territories number 3, num-
m
430
ber 37 and number 44-University Hill Farm, Madison, Wis.
(Property of the University of Wisconsin.)
At the beginning of the studies in 1929, the food and cover
conditions on this 200-acre sample were both good, but an effort
was made to see how high the carrying capacity of the tract
could be raised through intensive management. Different types
of shelters and feeding stations were also tested.
Grazing was excluded from all brushy lands, and all "clean-
ed up" practices involving the destruction of brushy cover were
discontinued. Clumps of conifers were planted at strategic
places, sometimes adjacent to plantings of vigorous thorny rose
bushes (Rosa setigera, R. rubiginosa). The conifers (Picea spp.
Abies spp., Pinus spp.) were planted as 4 to 6-foot trees, to pro-
vide a certain cover value from the beginning. Brush piles of
various sizes and types were erected here and there over the
place.
Artificial feeding during the first winter was done mainly by
means of wheat bundles, used both apart from and in connection
with shelters and brush piles.
By the second winter, cover conditions had improved
materially on those portions of the area protected from grazing
[see Leopold (48, fig. 28 facing p. 316)]. Corn shock feeding
stations were freely distributed in desirable places. These im-
provements apparently resulted in the establishment of a new
covey territory in an "odd corner" not previously occupied with
any regularity. As the birds ordinarily had easy access to much
food in the fields, the corn shocks were used only during severe
weather, but at such times they were of indubitably valuable
service.
During the third winter, cover conditions were about the
same as those of the winter before, but most of the food in the
fields was either closely harvested or plowed under. The main
reliance of the birds, then, was upon the artificial feeding sta-
tions. The feeding program was conducted on a truly substan-
tial scale and seemed to offset with fair adequacy the shortage
of food in the fields.
For both the second and third winters, the combined quail
and pheasant populations amounted to about one wild gal-
linaceous bird per 2.6 acres, an evident rise from the average
(but fluctuating) stand of about one gallinaceous bird per
acres for 1929-30. This rise was attributed to the improvement
of food and cover conditions, although we think it highly prob-
able that the same results could have been obtained with far
less expense and effort; much of the environment improved
was already strong, and the added improvements made no per-
ceptible difference to the security of the resident birds.
During the fourth winter, cover conditions were much as
before, but the supply of food in the fields was exceedingly
short. No artificial feeding was done, and, as a consequence,
431
no quail and few pheasants found the area regularly habitable
Experimental Area II, including territories number 9, num-
ber 21 and number 22-Fort Des Moines, Iowa. (Property of
U. S. Army.)
The sample observational area of about 1 square mile has
yielded data of value chiefly in that they have shown the effect
of plant succession on the habitability for quail of land with-
drawn from cultivation.
Roughly, one-half of the square mile lay in the form of a
wooded creek valley, and the other half in uplands which had
been planted to cultivated crops prior to 1932. The plant growth
on the land formerly cultivated was productive of a consider-
able amount of quail food (lesser ragweed and smartweed) dur-
ing the summer of 1932; much less so in the summer of 1933;
then, a wholly unexpected growth of lesser ragweed occurred in
1934, possibly as a result of the season's drouth.
The nesting conditions on the area and cover relations gen-
erally have been uniformly excellent, and strong populations of
quail have been observed each fall. The winter environment,
however, was deficient from the standpoint of food in 1932-33
and still more so in 1933-34; and the tendency of the populations
was to move off the area to adjacent private lands still in culti-
vation. Food patches were planted and feeding stations were
established by the Fish and Game Commission and the Fort Des
Moines staff cooperatively, but this artificially supplied food
until 1934-35 was apparently incapable of holding more than a
few coveys in competition with the winter attractions of culti-
vated fields outside-especially since many of the outside terri-
tories on privately owned farms seemed to be under-populated
by reason of fall poaching.
The food situation for the winter of 1934-35 was distinctly
improved, aside from the unexpectedly strong ragweed growth.
The artificial feeding program was in our judgment adequate
to take care of a carrying capacity population for the first time.
in the 3 years we have had the area under observation. The
food patches which held birds were those of fair size (from per-
haps a quarter to a half acre), conveniently accessible from good
cover.
Experimental Area III, including territories number 10,
number 23, number 24 and number 60 Des Moines, Iowa,
Waterworks Supply Grounds Park and Wildlife Refuge.
(Property, city of Des Moines.)
According to Mr. A. F. den Boer, superintendent of grounds,
(letter July 12, 1935), there were at least six coveys of quail on
the 1,506 acres of the supply grounds before 1930. These, at 15
birds per covey, would amount to 90 birds or one per 16.7 acres.
Varying numbers lived on adjacent cultivated private lands.
Cover conditions were excellent on the whole, but the land
432
had not been cultivated for years, to the natural deterioration of
the food types necessary for the wintering of bob-whites. Win-
ter feeding begun in 1928 offset materially the consequent food
shortage.
In the summer of 1932, at Mr. den Boer's invitation, the area
was inspected and specific recommendations made as to the
establishment of feeding stations. These recommendations
were followed thoroughly, and a sample area of 300 acres prov-
ed very valuable for purposes of study.
The sample 300 acres under heavy feeding wintered a popu-
lation of at least 55 quail in 1932-33, and nearly 100 in 1933-34.
In order to note the effect of a lapse in feeding operations,
we requested that no feeding be done on the sample area in the
fall of 1934. The initial fall population was insecurely situated
and very restless, and, although feeding in the chief coverts was
resumed later in the winter, a population of only 33 birds finish-
ed the season on the 300 acres.
The Waterworks data demonstrate, as well as any we have,
the importance of an adequate winter feeding program to quail
management on primarily uncultivated land. While the quail
were fed only in connection with the feeding of bird life gener-
ally over the area, and the feeding was done at some expense
and purposefully on a scale perhaps a trifle lavish, nevertheless
there is a practical lesson here to be gained on one of the things
that constitute truly effective management.
Experimental Area IV, including territories number 49,
number 50 and number 51-Ledges State Park, Boone, Iowa.
(Property of Iowa Conservation Board.)
Most of the 500-acre tract under observation is wooded, but
some parts are cultivated, thus furnishing an excellent habitat
for a limited number of quail coveys. On this tract, through
cooperation of Mr. Carl Fritz Henning, custodian, a type of
feeding station was devised and tried out-brush pile contain-
ing grain-which proved to be extremely effective in giving
bob-whites maximum protection from enemies.
Experimental Area V, including territories number 67 and
number 68-Privately owned farm land, south of Ottumwa,
Iowa.
The tract of about 800 acres under observation was set up
on private lands as a Bob-white Management Demonstration
Area by the Iowa Fish and Game Commission in 1932. This
area represented good quail country to begin with, and an
attempt was made to improve it further by planting of food
patches.
Of the six food patches experimentally planted, only one
(see territory number 68) proved to have any apparent in-
fluence in raising the carrying capacity of the land. This was
located in a cleared space in the woods, at a considerable dis-
433
tance from regularly habitable winter territories. The addition.
of the food in this case made habitable a potential territory
which previously had not been available. The other food
patches simply furnished more food to occupied territories.
which already had enough for the ordinary needs of their
occupants.
All in all, the experimentation upon definite areas has had as
its purpose the testing of management measures suggested by
the field studies. Food and cover manipulations have received
primary emphasis for the reason that they have shown the
greatest promise.
Predator control by direct action against predatory species
themselves has not been emphasized, as the field studies have
indicated very strongly that such would be neither desirable
nor efficacious. Aside from a certain amount of hunting and
trapping for fur and sporadic hawk and owl shooting by hunters
and farmers, predators have not been greatly molested on the
majority of the observational areas during the period of study.
On but two experimental areas were concerted attempts known
to have been made to reduce the resident predator populations,
and in neither case could any resulting benefit to quail be recog-
nized [Errington and Hamerstrom (35)].
It is significant that on areas, I, III and IV, the three experi-
mental areas demonstrating the greatest increase or security of
quail populations, hawks and owls were not only tolerated but
protected, and on area IV a goodly representation of predatory
mammals was also to be found. It is so far apparent that quail
populations may be about as well maintained at satisfactory
levels when predators are many as when they are few, at least
within the limits with which our studies have dealt.
Experimentation with the land has not realized its poten-
tialities for bob-white management anywhere. Stoddard has
been doing a great deal of work in the Southeast; Leopold et al,
in Wisconsin; other investigators, here and there. Bob-white
management has been practiced incidental to soil erosion pro-
jects, and Holt (41) has reported for the 90,000-acre Coon Val-
ley, Wis., tract an increase of 96 percent in winter population in
1 year's time, despite some adverse circumstances. A few more
examples might be listed to illustrate what is being done, but
work in this field of endeavor is barely getting started.
As Stoddard (letter, Aug. 27, 1935) writes of the Southeast:
"As far as my observations go, this is the only portion of the
country where quail management has been practiced long
enough, through good seasons and bad, to get much of a line
on results." What the ultimate significance of management may
be depends largely upon what is done and how well.
434
CONCLUDING REMARKS ON MANAGEMENT
Effective northern bob-white management comprises in the
main: 1. The raising of the carrying capacity of the land to a
satisfactory level or maintaining it there; 2. the strengthening
of individual coverts to protect against emergencies such as
blizzards and ice storms; and 3, the wise regulation of the
human toll upon the species incidental to hunting. Prospective
managers should be cautioned that misguided management
may lower instead of raise carrying capacity for quail. Particu-
larly is this true on lands that are withdrawn from cultivation
and on which the natural plant succession results in the sup-
planting of quail-food vegetation, as ragweed, by vegetation of
lesser value. Deterioration of quail environment may be virtu-
ally a certainty in the majority of instances unless the dimin-
ishing of the naturally available food supply is offset by artifical
feeding or by some continued cultivation.
Experience on game management areas has shown that ef-
forts to raise carrying capacity are more likely to be fruitful if
emphasis is placed upon the creation of new covey territories
a quarter mile or more distant from territories already occupied.
Potential territories strong in either food or cover but deficient
in either one or the other may lend themselves exceptionally
well to improvement measures.
Satisfactorily located but foodless coverts when supplied
with food patches or feeding stations may raise environmental
carrying capacity for bob-white, as may open corn or soybean
fields when made habitable as territories by the erection of
brush piles or the encouragement of dense, shrubby growths
along the edges.
Any formula for the management of bob-white which we
may try to express at this time could doubtless be refined to
advantage as we gain in knowledge. The best management
technique we may ever devise will never be infallibly produc-
tive of desired results. Quail with or without evident cause
may not use territories provided for them. The chance that
things may not work out according to hopes is a chance which
must be taken by everyone who concerns himself with the
management of a wild species, which, after all, does consider-
ably as it pleases.
That continued investigation is the price of greater know-
ledge should be accepted without question. Wildlife manage-
ment, to be more than mere tinkering with natural mechanisms,
needs not only skilled technicians but man-power capable of
difficult ecological research. Persons capable of research can
be trained but slowly, for scientifically acceptable research in
this field demands abilities equivalent to those demanded by
other sciences [Errington (27)].
435
Administration of wildlife resources is a field in itself and, to
be done properly, requires a personnel with background and
ability, courage and tact. The ideal administrator must be able
to carry on his work with a minimum of entangling politics
and at the same time keep reasonably up to date with the pro-
gress of significant research. Among other things, he must be
able to recognize what constitutes the permanent interests of
society and that the duty of a leader is to lead. And in addition,
he must be able to guide the mass public, guide them well and
make them like it.
The necessity for more harmonious integration of human
interests has been touched upon. The first conflicts in human
interests doubtless began as soon as there were interests to
conflict. Whatever may be the ethical or the biological or the
economic aspects of human controversies, the premise is logical
that unnecessary friction between groups of people working for
a broadly common end imperils the attainment of that end, re-
gardless of how worthy or how desirable of attainment it may
be.
We are convinced that there is at least some wholly unneces-
sary friction between sportsmen and protectionists, in particu-
lar. These are two important factions whose one general goal,
as repeatedly expressed in their publications, is the conserva-
tion of wildlife, non-game species as well as game.
We are aware that shooters exist whose immediate aim is
to shoot while they may, irrespective of conservation; and that
there are non-shooters who care less for conservation than for
the prohibition of shooting. These two extremes may never
agree on anything except mutual opposition, but great numbers
of sportsmen and protectionists have intermediate viewpoints
that should not be quite so irreconcilable.
It seems probable to us that very few sportsmen would
deliberately oppose complete legal protection for hunted wild
species which they really thought would meet extinction if not
given complete protection and which they thought protection.
would save. Moreover, it seems probable that many of the most
militant protectionists would not oppose shooting for sport if
they thought that the shooting were being done without actual
detriment to the wild populations (especially native species)
directly and indirectly affected.
The bob-white is an example of a wild species about which
sportsmen and protectionists have long waged bitter contro-
versy, replete with extravagant statements and recrimination.
That this controversy should continue with little abatement is
especially regrettable in view of the fact that so much of it does
not take into account the reliable information to be had.
•
436
The provision or maintenance of a suitable environment for
the bob-white is of foremost importance, yet of all the things
that should never be neglected, this is the one that most fre-
quently is. At the same time, stress-far out of proportion to
their value-continues to be laid upon legal protection, predator
control, stocking of lands with artificially propagated or im-
ported birds, and other measures that do not remedy funda-
mental environmental defects.
It has been the observed tendency of sportsmen to magnify
the depredations of predators upon game and to minimize the
effect of hunting. On the other hand, protectionists have tended
to magnify the role of hunting as a decimating factor and to
minimize the effect of environmental impoverishment, prevent-
able or unavoidable. The central issues have been further ob-
scured by the perennial argument about inbreeding and by the
mutual intolerance and skullduggery from which the strife has
not been entirely free.
The sportsman's over-emphasis upon predator control and
the protectionist's fear that the bob-white is in continual danger
of extermination from over-shooting have been never-failing
sources of friction between the two groups. It is hoped that the
evidence presented in this bulletin may be a means toward bet-
ter understanding.
Much of the friction has been due to the failure of the
sportsman to recognize that predation upon wing-clipped birds
crowded into a rearing pen on a game farm is a different thing
from predation upon unhandicapped birds living in the wild
under conditions favoring easy escape. Much of the sports-
man's animus may trace to observed predation upon over-popu-
lations or upon populations conspicuously vulnerable from
some cause. The truth of the matter is that predators feed
largely upon what prey, game or non-game, that they are able
to catch and handle with the least trouble, whether that prey be
wild or domesticated; as long as life exists, life will exist to
prey upon it, in one way or another.
Leopold (54), (47), (50), (52), has ably written upon the
bad aesthetics and the bad politics of ruthless intolerance on
the subject of predators. McAtee's (55), (57), (59) essays on
predators are much to the point. Some degree of control of
some predators will probably always be to the public interest,
but discretion should be used as to what predators are to be
subject to control and when, where, and how much. The preju-
dices on this subject, however, are so innate and have gained
such terrific momentum, and the plight of so many predatory
species is so serious, that efforts could well be made to curtail
persecution wherever circumstances permit.
Since there is no apparent justification for stringent preda-
tor control in the management of the northern bob-white, and
437
since the species, given favorable environment, is able to with-
stand considerable shooting as well, it would seem that as con-
cerns this bird a substantial portion of both hunters and protec-
tionists have less cause for dissension than they may think.
This writing does not contend, nor, in any way, imply that
all friction between sporting and protectionist groups may in
all respects be eliminated. It does submit that some of the con-
tested issues are not worth the turmoil that they have
occasioned.
Leopold (52), referring to the sportsman-protectionist dead-
lock, warns-"that sportsmen and zoophiles have a common
enemy of vastly greater importance to both than any real con-
flict of interest over hawks, ducks, or the legitimate uses of
gunpowder. That enemy is public indifference. The basic issue
in wildlife conservation is whether machine-made man, who
outnumbers us five to one, really cares enough about wild
things to steer the industrial juggernaut around our interests.
We [the sportsmen] and the zoophiles are like two small boys
quarreling in the street over marbles, unmindful of what is com-
ing down the hill. Unless we make common cause, we bid fair
to make only a common grease-spot on the broad highway of
progress.
,,
To many of those who may question the worthwhileness of
bob-white management, or the broader wildlife management or
the still broader conservation of natural resources, we may not
be able to give a very convincing answer. But others may see
something of an answer in a final quotation from Leopold (48,
p. 388):
(6
To see merely what a range is or has is to see
nothing. To see why it is, how it became, and the direction and
velocity of its changes-this is the great drama of the land, to
which ‘educated' people too often turn an unseeing eye and a
deaf ear. The stumps in a woodlot, the species age and form of
fencerow trees, the plow-furrows in a reverted field, the loca-
tion and age of an old orchard, the height of the bank of an irri-
gation ditch, the age of the trees or bushes in a gully, the fire-
scars on a sawlog-these and a thousand other roadside objects
spell out words of history of the recent past and the trend of the
immediate future
"Biological science, if it had no economic import at all,
would nevertheless be justified by its enrichment of the human
faculty for observation. Jason, Eric, Magellan, Daniel Boone,
saw only the cover of the Great Book. Its free translation is the
unique privilege of post-Darwinian explorers. To this first gen-
eration of game managers, especially, is offered many a virgin
page."
438
SUMMARY
This bulletin is based upon the data from intensive popula-
tion studies which have been carried on with the bob-white
quail over a period of six winters, largely in Iowa and Wiscon-
sin agricultural communities. Populations of the bob-white and
other wild species have been kept under observation on specific
areas for consecutive seasons in order to obtain something of
an insight into the ecological mechanisms that govern animal
numbers.
Direct enumeration census technique proved to be most
useful and reliable in the field researches. Emphasis was placed
upon determining the number of bob-whites wintering in a
given area and in recording and ascertaining the reasons for
any changes in population levels through movements or mor-
tality. The evaluation, as much as possible, of the winter role
of food, cover, covey territory, behavior and predation in the
life history of the bob-white has been considered of primary
importance.
Survival data from the 70 specific bob-white wintering terri-
tories or groups of territories which have been studied for more
than one season indicate that a given tract of environment is
capable of accommodating a rather definitely limited population
even under optimum weather conditions. The carrying capacity
of a tract of land for bob-whites seems generally to remain
about the same from one year to the next, although the carry-
ing capacity of each tract of land is by no means the same. Con-
stancy of carrying capacity has been much more apparent on
large land units than on small.
Carrying capacity of quail environment doubtless changes
gradually over a period of years, despite the fact that on our
chief observational areas it has remained practically constant
for as long as 6 years. It is true that given quail environment
may often withstand a surprising degree of change without
having its carrying capacity appreciably affected, but carrying
capacity may be either raised or lowered artificially. What
actually determines carrying capacity of quail lands we cannot
explain in detail, except that it seems linked with the quality
and distribution of food and cover and with the intolerance of
over-crowding displayed by the birds themselves.
The correlation between severity of predation upon winter-
ing bob-whites and carrying capacity of their environment is
especially significant. Losses from simple predation suffered
by wintering populations within the carrying capacity of their
environment, as measured to date, have been uniformly light,
rarely at a rate exceeding 6 percent per 90 days. On the other
hand, when areas were over-populated, either the over-popula-
tions were soon reduced by the departure of the excess birds, or
439
were reduced sooner or later before spring by mortality, usually
from enemies. With the vulnerably situated surplus populations
gone, the survivors were noted to enjoy a relative security from
mortality through predation, except when weakened or handi-
capped as by starvation, wounds, disease, etc.
While over-populations of wintering bob-whites are com-
monly reduced through the medium of predation to levels more
securely accommodated, the kinds and numbers of the preda-
tors do not appear to make a great deal of difference in bringing
this about. Populations which were insecure for some reason—
notably those portions which were forced into unfavorable
environment by crowding or by eviction by man or emergencies
from stronger habitats—exhibited a distinct vulnerability to
predation, whether predators, within limits observed, were few
or many, and whether the predators were or were not of the
most formidable types.
Similarly, within limits observed, the comparative abun-
dance of "buffer" species, i. e., mice, rabbits and others which
regularly bear the brunt of predator attacks did not appear to
make perceptible difference in the intensity of predation suffer-
ed by wintering bob-whites. This is probably explainable, at
least in part, by the fact that quail seem to be preyed upon more
incidentally as they happen to be available than they are eaten
as a staple food. Indeed, it probably seldom happens that quail
ever constitute enough of an item in the diet of a given predator
to rank as a principal food, and we have no evidence that any
predator is likely to be dependent upon quail for food under
any ordinary circumstances. There are many things which as
a rule may be captured for prey with far greater ease than quail
except when the latter are rendered vulnerable from some
cause.
·
On the whole, our evidence indicates that the pressure of
native enemies is unlikely to be sufficiently severe to reduce
healthy, well-fed wintering bob-white populations below the
carrying capacity of the land. Populations may be reduced be-
low carrying capacity, however, by shooting or trapping, by
starvation or other emergencies associated with snow or ice
storms, by drouth, and probably by disease and unknown fact-
ors. Concentrations of the exotic ring-necked pheasant in
coverts of strategic importance for quail may cause the latter to
avoid those coverts, and may thus in effect lower the carrying
capacity of the land for the quail themselves.
The seasonal recovery rates of bob-white populations
through breeding during the summer apparently have some
relation to the position of the spring seed stock level with
respect to the fall and winter carrying capacity of the land. The
limited data at hand point to considerably higher rates of in-
440
crease for breeding populations which have been drastically
reduced previously by emergencies, over-shooting, etc., pro-
vided that the surviving birds are well situated in strong
environment.
In the conservation on the management of the bob-white, a
few simple measures are to be recommended. The habitability
of the environment for quail should be improved or maintained,
and this demands particular attention to food and cover. The
quail should be subjected to no more than moderate shooting
and then only where the species is well established. Intensive
campaigning against native predators is not advised, save per-
haps under exceptional circumstances where such might be
locally desirable; predator control is no substitute for food and
cover, and practically all control efforts that we have witnessed
in the North have been futile from the standpoint of bob-white
management, if not actually detrimental.
All in all, a sound conservation program for the bob-white
could well be integrated with a sound program of land use. The
bob-white thrives best as a farm species, and the agricultural
practices which tend to evict this bird are to a large extent the
same practices which tend to evict man himself from the soil.
Truly effective bob-white management may be closely cor-
related in many communities, for example, with the control of
soil erosion, of basic significance to permanent agriculture.
441
(2)
(3)
(4)
(5)
(6)
LITERATURE CITED
Allee, W. C. Animal aggregations. Chicago. 1931.
Bennett, H. H. Soil erosion - a national menace. Scientific
Monthly, 39:385-404. 1934.
Bennett, H. H. Facing the erosion problem. Science, 81:321-326.
1935.
Bennett, L. J. A comparison of two Iowa duck nesting seasons.
Trans. 21st American Game Conference, American Game As-
sociation: 277-282. 1935.
Chapman, R. N. Animal ecology. McGraw-Hill. 1931.
Dalke, Paul D. Carrying capacity of pheasant range. American
Game, 24:23, 31-32. 1935.
(7) Darling, J. N. Desert makers. Country Gentleman, 105 (10):5-7,
81. 1935.
(8) Elton, Charles. Periodic fluctuations in the numbers of animals:
their causes and effects. Brit. Jour. Exp. Biol. 2:119-163. 1924.
(9) Elton, Charles. Animal ecology. MacMillan. 1927.
(10) Elton, Charles. Animal ecology and evolution. Humphrey Mil-
ford, London. 1930.
(11)
Errington, Paul L. Winter killing of barn owls in Wisconsin.
Wilson Bul., 43:60. 1931.
(12)
Errington, Paul L. The bob-white's winter food. American
Game, 20:75-78. 1931.
(13)
(14)
(15)
(16)
Errington, Paul L. Great horned owls dying in the wild from
disease. Wilson Bul., 44:180. 1932
Errington, Paul L. Studies on the behavior of the great horned
owl. Wilson Bul., 44:212-220. 1932.
(17)
(18)
Errington, Paul L. Mobility of the northern bob-white as indi-
cated by banding returns. Bird Banding, 4:1-7. 1933.
(19) Errington, Paul L. Food habits of southern Wisconsin raptors-
Part II. Hawks. Condor, 35:19-29. 1933.
Errington, Paul L. The bob-white's winter cover. American
Game, 20:90-93. 1931.
Errington, Paul L. Technique of raptor food habits study. Con-
dor, 34:75-86. 1932.
Errington, Paul L. Food habits of southern Wisconsin raptors-
Part I. Owls, Condor, 34:176-186. 1932.
(20) Errington, Paul L. The wintering of the Wisconsin bob-white.
Trans. Wis. Acad., Sci., Arts, and Letters 28:1-35. 1933.
(21) Errington, Paul L. Another winter's quail study. American
Game, 22:39, 44-45. 1933.
(22) Errington, Paul L. Management of the bob-white quail in Iowa.
Iowa State College, Ext. Bul. 186. 1933.
(23) Errington, Paul L. Bob-white winter survival in an area heavily
populated with grey foxes. Iowa State College Jour. Sci.,
8:127-130. 1933.
(24) Errington, Paul L. Summer bob-white observations in a city
backyard. Iowa Bird Life, 3:36-37. 1933.
(25) Errington, Paul L. The nesting and the life equation of the Wis-
consin bob-white. Wilson Bul., 45:122-132. 1933.
(26) Errington, Paul L. Vulnerability of bob-white populations to
predation. Ecology, 15:110-127. 1934.
(27) Errington, Paul L. Wild life research as a profession. Scientific
Monthly, 38:554-560. 1934.
(28) Errington, Paul L. Predators and the northern bob-white. Amer-
ican Forests, 41 (1):7-10, 46. 1935.
(29)
Errington, Paul L. The 1934 drought and southern Iowa bob-
white. Iowa Bird Life, 5:18-21. 1935.
442
(30) Errington, Paul L. Food habits of mid-west foxes. Jour. Mam-
malogy, 16:192-200. 1935.
(31) Errington, Paul L. Over-populations and predation: a research
field of singular promise. Condor, 37:230-232. 1935.
(32) Errington, Paul L. The winter of 1934-35 and Iowa bob-whites.
American Midland Naturalist, 17:554-568. 1936.
(33)
Errington, Paul L. and Bennett, Logan J. Lost legions (An article
dealing with game birds lost incidental to hunting.) Outdoor
Life, 72 (3):18, 19, 56. 1933.
(34) Errington, Paul L. and Bennett, Logan J. Iowa duck studies.
Trans. 20th Amercian Game Conference, American Game As-
sociation: 249-257. 1934.
(35) Errington, Paul L. and Hamerstrom, F. N. Jr. Bob-white winter
survival on experimentally shot and unshot areas. Iowa State
College Jour. Sci., 9:625-639. 1935.
(36) Gause, G. F. The struggle for existence. Williams and Wilkins.
1934.
(37) Grange, W. B. and McAtee, W. L. Improving the farm environ-
ment for wild life. Farmer's Bul. 1719, U. S. Dept. of Agr.
1934.
(38) Green, R. G. and Wade, E. M. A natural infection of quail by B.
tularense. Proc. Soc. Exper. Biol. and Medicine, 26:626-627.
1929.
(39) Green, R. G. and Shillinger, J. E. Wildlife cycles and what they
mean to the grouse supply. Trans. 20th American Game Con-
ference, American Game Association: 182-185. 1934.
(40) Green, R. G. and Shillinger, J. E. Progress report of wildlife dis-
ease studies for 1934. Trans. 21st American Game Confer-
ence, American Game Association: 397-401. 1935.
(41) Holt, E. G. The soil erosion service and wildlife. Trans. 21st
American Game Conference, American Game Association:
319-325. 1935.
(42) Howard, H. E. Territory in bird life. E. P. Dutton and Co., New
York. 1920.
(43) Kendeigh, S. C. Abundance and conservation of the bob-white
in Ohio. Ohio Jour. Sci., 33:1-18. 1933.
(44) Kendeigh, S. C. The role of environment in the life of birds.
Ecological Monographs, 4:299-417. 1934.
(45) Leopold, Aldo. Wilderness as a form of land use. Jour. Land and
Public Utility Economics, 1:398-404. 1925.
(46) Leopold, Aldo. Report on a game survey of the north central
states. Sporting Arms and Ammunition Manufacturers' In-
stitute, Madison, Wis. 1931.
(47) Leopold, Aldo. Game methods-the American way. American
Game, 20:20, 29-31. 1931.
(48) Leopold, Aldo. Game Management. Scribners. 1933.
(49) Leopold, Aldo. The conservation ethic. Jour. Forestry, 31:634-
643. 1933.
(50) Leopold, Aldo. The American game policy on predators. Out-
door Life, 71 (4):25. 1933.
(51) Leopold, Aldo. Conservation economics. Jour. Forestry 32:537-
544. 1934.
J
(52) Leopold, Aldo. Whither 1935?-a review of the American Game
Policy. Trans. 21st American Game Conference, American
Game Association: 49-55. 1935.
(53) Leopold, Aldo and Ball, John N. The quail shortage of 1930. Out-
door America, 9 (April): 14-15, 17. 1931.
443
(54) Leopold, Aldo et al. (Committee). Report to the American Game
Conference on an American game policy. Trans. 17th Ameri-
can Game Conference, American Game Association: 284-309.
1930.
(55) McAtee, W. L. A little essay on vermin. Bird Lore, 33:381-384.
1931.
(56) McAtee, W. L. Effectiveness in nature of the so-called protective
adaptations in the animal kingdom, chiefly as illustrated by
the food habits of Nearctic birds. Smithsonian Misc. Coll.,
85 (7) (Publ. 3125). 1932.
(57) McAtee, W. L. Game management is not just vermin control.
Outdoor Life, 72 (5):24-25. 1933.
(58) McAtee, W. L. Rejoinder to papers on protective adaptations.
Proc. Royal Entomological Soc. London, 81:113-126. 1934.
(59) McAtee, W. L. Conservation of game or of wild life-which?
Scientific Monthly, 38:165-169. 1934.
(60) McAtee, W. L. The Malthusian principle in nature. Scientific
Monthly, 42:444-456. 1936.
(61)
(62)
Matamek Conference on Biological Cycles, 1932, 1933.
Nice, M. M. The theory of territorialism and its development
Fifty years progress of american ornithology; American Or-
nithologists Union Memorial Volume. Lancaster, Pa. 88:89-
100. 1933.
(63) Nice, M. M. Zur Naturgeschichte des Singnammers. Jour. für
Ornithologie, 81:552-595. 1933.
(64) Nice, M. M. Zur Naturgeschichte des Singnammers. Jour. für
Ornithologie, 82:1-96. 1934.
(65) Nice, M. M. Song sparrows and territory. Condor, 36:49-57. 1934.
(66) Nice, M. M. Studies in the life history of the song sparrow. Lin-
naean Soc. N. Y. 1936.
(67) Nicholson, A. J. The balance of animal populations. Jour. of Ani-
mal Ecology, 2:132-178. 1933.
(68) Schuenke, Wm. Reports on 1933 experimental quail shoot on
official quail management areas in Iowa. Iowa Fish and
Game Commission (mimeographed report). 1933.
(69) Severtzoff, S. A. On the dynamics of populations of vertebrates.
Quart. Rev. Biol., 9:409-437. 1934.
(74)
(75)
(70) Stoddard, H. L. The bob-white quail. Scribners. 1931.
(71) Stoddard, H. L. Second Annual Report (1933-34) Cooperative
Quail Study Association. Thomasville, Ga. 1934.
(72) Stoddard, H. L. The use of fire on south-eastern game lands.
Cooperative Quail Study Association. Thomasville, Ga. 1935.
(73) Taylor, W. P. Significance of extreme or intermittent conditions.
in the distribution of species and management of natural re-
sources, with a restatement of Liebig's Law of Minimum.
Ecology, 15:374-379. 1934.
Taylor, W. P. “Man and Nature”—a contemporary view. Scien-
tific Monthly, 41:350-362. 1935.
Tinbergen, N. Die ernährungsökologischen Beziehungen zwischen
Asio otus otus L. und ihren Beutetieren, insbesondre den
Microtus-arten. Ecological Monographs, 3:443-492. 1933.
(76) Wight, H. M. Quantitative methods in upland game bird investi-
gation. Auk. 48:553-558. 1931.
(77) Wing, L. W. Wildlife cycles in relation to the sun. Trans. 21st
American Game Conference, American Game Association:
345-363. 1935.
!
UNIVERSITY OF MICHIGAN
3 9015 02708 9260
i
ཀ
}
A
BOUND
Str 22 1947
UNIV. OF MICH.
LIBRARY

}
!
1