Desert Bighorn Sheep Desert bighorn sheep symbolize the rugged spirit of the American West. Living in rocky desert canyons, they, peccary, and deer are the only native, hoofed animals now surviving in the harshest areas of our southwestern deserts. However, poor habitat condi- tions, lack of water, and human disturbance have caused desert bighorn sheep populations to drop from several hundred thousand to less than 16,000 over the last 150 years. Bighorn sheep, named by early pioneers, are best known for the rams' huge horns. The horns grow in a tight circle and can weigh up to 30 pounds. They are not shed each year like antlers; in fact, a ram's age can be determined by the growth rings on his horns. The ewes' horns are smaller, more slender, and more spiked than the rams'. They curve back slightly and only grow to about 12 inches. The hooves of the bighorns have two toes sepa- rated by a soft central pad, which enables them to grasp jagged rocks. These special hooves permit them to scramble and zigzag over steep, craggy cliffs in the rocky areas where few other large animals can live. In addition, their springy bodies are well suited to leaping up or dropping down a nearly vertical rock, or barely pushing off narrow outcroppings of "bald" desert mountains with little vegetation. UNIVERSITY OF , nn ILLINOIS LIBRARY NOV 01 199U AT URBANA-CHAMPAIGN (/ . frll , of ILUNOIS BOOKSTACK3 ^rSma-champaigm Desert bighorns are smaller than their mountain cousins — the rams typically weigh about 160 pounds, and the ewes, 105 pounds. They have a thin, buff-gray coat which is similar in texture to that of a deer or elk. This coat helps to regulate their body temperature during the cold nights and hot days on the desert. Keen vision enables the bighorns to protect themselves from predators — they can see up to 5 miles away! With their amber-yellow eyes on the sides of their heads, bighorns can see behind themselves. Their acute senses of hearing and smell also warn them of attacks from predators, such as mountain lions and coyotes. Life Cycle — Mating season usually occurs in late summer. Older rams will occasionally hold head- butting contests to win the right to mate with ewes. With about 10 yards separating them, their ears back and heads lowered, they run forward, lunging and smashing their horns together in a violent crash that echoes up to a mile away. Their strong horns, skulls, and necks act as a shock absorber against the impact. The crash may stun the animals, but with a shake of their heads the rams are ready to back up and repeat the charge. The rams grunt, snort, and kick each other with their front legs. These contests may last for hours, until one ram backs off, drops from exhaustion, or is knocked out cold The ewes mature and begin mating at about age 3. Most ewes bear only one lamb a year, but some occasionally have twins. Lambs are born in late winter on high, narrow slopes, safe from predators and adjacent to water and vegetation. Ewes will only tend to their own young — an orphaned lamb is left to die. The lambs can walk after only a few hours and can run and jump within days. As they get older, lambs play games like "follow-the-leader" and "king of the mountain." They also fight and challenge each other in competitions of strength and agility. Ewes typically travel in bands with their new lambs and 1- and 2-year-old offspring. At about age 3, young rams leave these groups to travel alone or in small bands. Older rams leave their mates after the lambs are born, travel in bachelor bands during the spring and early summer, and then rejoin ewes in time for the next mating season. Survival — Desert bighorn sheep generally stay in the same area for their entire lives, which rarely exceed 10 years. They live where their ancestors lived and return annually to the same location for mating and giving birth. Herds may number more than a hundred animals, but most are smaller. The sheep eat a variety of grasses, shrubs, and other plants containing moisture during the winter season. During hot, dry, desert days, the bighorns rely on good water supplies and get supplemental moisture from water-holding plants like cacti. Having no upper front teeth, they must hold and mash vegetation between their lower front teeth and the homy pad of their upper front jaws, jerking their heads to break off vegetation. Competition for forage between bighorns and livestock, loss of water supplies, and disease have all been factors contributing to the decrease in population of desert bighorns since the 1800s. More recently, encroachment by humans upon bighorn habitat has become a growing problem. Poorly designed wire fences can also result in injury to bighorns, and poaching continues to be a problem in some areas. Bighorns Need Help Eighty percent of desert bighorn habitat — nearly 9 million acres — is in six western states on public land managed by the Bureau of Land Management (BLM). For the last two decades, BLM has worked with State agencies and private groups to develop water sources, improve vegetation conditions, and protect habitat areas from human disturbance. The key to preserving this American treasure is to improve its habitat. Additional actions undertaken by bighorn enthusiasts, BLM, and State wildlife manage- ment agencies include reintroducing bighorn sheep into ranges they previously inhabited. Because the desert bighorn is more likely to survive when surface water is available, the promotion of suitable water supplies is a primary effort of BLM and its volunteers. The construction of artificial water catchments, such as guzzlers, ensures storage of winter runoff, which is then available during critical summer months. Managing vegetation around waterholes is also important. Water-hungry shrubs are discouraged in order to increase the flow and access of water. In addition to ensuring adequate water, these critical areas must be protected from human encroachment to allow bighorns to use available water sources without fear. Other BLM efforts to improve bighorn habitat include: management of livestock grazing, building safe fences, regulating excessive recreation near sensitive habitat, and managing populations of competing animals. UNIVERSITY OF ILLINOIS LIBRARY AT URBAN AC I A. .. ;N Dec. X 5 3. A COLORADO BLM Lands Category II — Remnant or Reintroduced Herds I Category III — Historical Habitat UNIVERSITY OF ILLINOIS-URBANA 3 0112 084233474 How You Can Help In 1989, BLM published its "Rangewide Plan for Managing Habitat of Desert Bighorn Sheep on Public Lands." The goal of the plan is to recover populations of desert bighorn in six states — Arizona, California, Colorado, Nevada, New Mexico, and Utah. Each state will develop a more specific plan to establish local objectives within the scope of the Rangewide Plan. In Colorado, desert bighorn are found only near the western border of the State. Habitat on BLM-admini- stered lands in Colorado is estimated at 400,000 acres along the major drainages and canyons of the Dolores River, along a small portion of the Gunnison River, and along the Colorado River near the Utah and Colorado border. Efforts to reestablish sheep in historic areas in southwest Colorado were initiated in 1974. These cooperative efforts culminated with an agreement among the Colorado Division of Wildlife, National Park Service, and BLM. After years of planning, the desert bighorns were reintroduced along the Colorado- Utah border. A total of 1 22 desert bighorns were released in Colorado between 1979 and 1987. The population as of fall 1987 was estimated at 210 animals, occupying about 100,000 acres of BLM-administered lands. The BLM Colorado State plan was published in 1989. As a part of the program, three herds were reintroduced into historic habitat areas. Other goals include improving and maintaining habitat, and introducing 200 additional bighorns into two new areas: Palisades/Sewemup and Lower Dolores River. A significant goal in Colorado is to support a statewide population of 500 animals by 1995, and a total of 1,2C by the early 21st century. Other aspects of the plan call for BLM to: • Enhance forage growth in habitat areas • Minimize disturbance to habitat during breeding • Develop bighorn watering structures • Minimize wire fence construction • Minimize mineral exploration in sensitive areas • Regulate recreation activities in sensitive are; Another successful tool for habitat recovery in Colorado is the challenge cost share program. Since 1985, Congress has provided "cost share" funding for desert bighorn projects, whereby the Federal govern- ment matches gifts of money, material, and labor donated by private individuals and organizations. The bighorn program remains focused on opening potential habitat for full use by these magnificent desert animals. Additionally, there is a continuing and growing need to maintain those water developments and other habitat improvements already constructed. Increased public involvement and support are needed and welcome. To find out what you can do, contact any of the agencies or groups listed below. Bureau of Land Management Rocky Mountain Bighorn Society Colorado State Office P.O. Box 1086 2850 Youngfield Street, CO-932 Denver, Colorado 80201-1086 Lake wood, Colorado 80215 Phone 303-494-5505 Phone 303-236-1762 Foundation for North American Wild Sheep Colorado Division of Wildlife 720 Allen Avenue 6060 Broadway Cody, Wyoming 82414 Denver, Colorado 802 1 6 Phone 307-527-6261 Phone 303-297-1 192 Copies of the Rangewide Plan are available from your local BLM office. A U.S. GOVERNMENT PRINTING OFFICE: 1990—776-312