DOC. 53.2: Sh3/Nev 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. 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. n \ ^ i 1990 UNIVERSITY Oi iLLrNOIS „-r iioHANA-nHAMPAIGN ^ U.S. Department of the Interior Bureau of Land Management 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 horny 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 URBANA-CHAMP/ N BOOKSTACKS Qoc, C5 3.5: Sh Z/\je\). NEVADA BLM Lands Category I — Viable Herds Category II — Remnant or ' ' Reintroduced Herds Category III — Historical Habitat .URBAN* 3 0112 084233466 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. Nevada has one of the largest populations of desert bighorn sheep in the United States. Early explorers in Nevada reported an abundance of bighorns. Today desert bighorns occupy 37 different mountain ranges on public lands in the southern two-thirds of the state. BLM biologists and managers in Nevada have been working with the Nevada Department of Wildlife, private individuals, and volunteer groups for well over 20 years to increase the bighorn population and enhance bighorn habitat. Nevada's desert bighorn program has three major strategies. The first is habitat improvement, including increasing the amount of water available in a habitat area. The BLM in Nevada has been very active in the area of water development — over 65 water sites have been developed for existing and reintroduced desert bighorn populations. Most of these developments — "guzzlers" and "slick-rock" — have been joint ventures between the BLM, Nevada Department of Wildlife, and volunteer groups through the BLM's challenge grant/ cost-share program. The second strategy in Nevada's bighorn program is the vigorous reintroduction of bighorns into historic ranges by the Nevada Department of Wildlife. Since 1968, the Department has made 46 desert bighorn releases totaling 665 animals on 20 different mountain ranges. Fourteen of the ranges have had two or more reintroductions. The Department has closely monitored these transplants to track bighorn movements and the overall success of the program, which has been very high. An additional nine historic ranges have been identified for future bighorn reintroductions. Land use planning is the third strategy of Nevada's desert bighorn program. General land use plans and specific habitat management plans have been developed to manage the often conflicting multiple uses of public lands. BLM land use plans have identified historic bighorn habitats suitable for reintroductions, as well as existing habitats. These plans now cover all public lands in Nevada. Site specific plans have been devel- oped for each initial reintroduction prior to the actual bighorn release. The Nevada Department of Wildlife and volunteers, along with other special interest groups and the general public, have provided major input to these plans during their formulation. Another successful tool for habitat recovery in Nevada 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 Nevada Bighorns Unlimited, Elko Desert Game Range Nevada State Office Box 2233 1500 North Decatur 850 Harvard Way Elko,NV 89801 Las Vegas, NV 89108 P.O.Box 12000, NV-931 Reno, Nevada 89520 Nevada Bighorns Unlimited, Fallon Fraternity of the Desert Bighorn Phone 702-328-6266 Box 2308 Box 27494 Fallon, NV 89406 Las Vegas, NV 89126 Foundation for North American Wild Sheep Nevada Bighorns Unlimited, Reno Nevada Department of Wildlife 720 Allen Avenue Box 21393 Box 10678 Cody, Wyoming 82414 Reno,NV 89515 Reno, Nevada 89520 Phone 307-527-6261 Phone 702-688-1500 Copies of the Rangewide Plan are available from your local BLM office. * U.S. GOVERNMENT PRINTING OFFICE: 1990—776-312