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The Handbook: Prevention and Control of Wildlife Damage Management, Internet Center Wildlife Damage for

January 1994

Pronghorn antelope (Antilocapra americana)

Sanford D. Schemnitz Professor, Wildlife Science, New Mexico State University, Las Cruces, New Mexico 88003

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Schemnitz, Sanford D., "Pronghorn antelope (Antilocapra americana)" (1994). The Handbook: Prevention and Control of Wildlife Damage. 52. https://digitalcommons.unl.edu/icwdmhandbook/52

This Article is brought to you for free and open access by the Wildlife Damage Management, Internet Center for at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in The Handbook: Prevention and Control of Wildlife Damage by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Sanford D. Schemnitz Professor Wildlife Science PRONGHORN New Mexico State University Las Cruces, New Mexico 88003 ANTELOPE

Fig. 1. Pronghorn antelope, Antilocapra americana

Identification Damage Prevention and Repellents The pronghorn (Antilocapra americana) Control Methods None are registered. is not a true antelope but in a family by Exclusion Toxicants itself (Antilocapridae). It is native only to North America. Woven wire and electric fence. None are registered. The pronghorn is the only North Cultural Methods Trapping American big game animal that has Plant tall-growing crops near damaged Corral trap. branched horns, from which its name fields. derives. Pronghorns have true horns Shooting — derived from hair — not antlers. Frightening Encourage legal hunting. The horns have an outer sheath of Gas-operated exploders. fused, modified hair that covers a per- manent, bony core. Pronghorns shed the hollow outer sheath each year in October or November and grow a new set by July. Both bucks and does have

PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994 Cooperative Extension Division Institute of Agriculture and Natural Resources University of Nebraska - Lincoln United States Department of Agriculture Animal and Plant Health Inspection Service Animal Damage Control D-71 Great Plains Agricultural Council Wildlife Committee and 1950s, limited hunting seasons struction of many highways with par- were permitted, and pronghorn sea- allel fencing has greatly altered the mi- sons have been held ever since in most gratory patterns of pronghorns. Great Plains states. Populations have Woven wire fences, in particular, are a shown a notable increase in the last 2 barrier that impede pronghorn move- decades. ments to water, wintering grounds, and essential forage. Proper spacing of A game management success story barbed wire in fences (Fig. 3) is essen- documents an increase from a popula- tial to allow adequate pronghorn tion low of a few bands of pronghorn movement. in Nebraska during the early 1900s to a current population of about 7,000. Trapping and transplanting programs Food Habits to reestablish pronghorn populations Pronghorns eat a variety of plants, by the state wildlife agencies and mostly forbs and browse. Sagebrush Fig. 2. Range of the pronghorn in North America. proper management and protection often makes up a large part of their have been major factors in the diet. They are dainty feeders, plucking horns, but doe horns are shorter and pronghorn’s recovery. only the tender, green shoots. more slender. Adult pronghorns stand Pronghorns compete with sheep for 3 feet (90 cm) high at the shoulders. Habitat forbs, but are often found on summer Bucks weigh about 110 pounds (50 kg); cattle ranges where cattle eat the Pronghorns thrive in short and mixed does weigh about 80 pounds (36 kg). grasses, leaving the forbs and browse. grasslands and sagebrush grasslands. Pronghorns have a bright reddish-tan Dietary overlap of pronghorns with They prefer rolling, open, expansive coat marked with white and black. The sheep and cattle was 40% and 15%, re- terrain at elevations of 3,000 to 6,000 buck has a conspicuous black neck spectively, in New Mexico. In the win- feet (900 to 1,800 m), with highest patch below the ears, which is lacking ter, pronghorns often feed in winter population densities in areas receiving on the doe. At a distance, their mark- wheat and alfalfa fields. ings break up the outline of their body, an average of 10 to 15 inches (25 to 38 cm) of precipitation annually. Vegeta- making them difficult to see. Their General Biology, white rump patch is enlarged and con- tion heights on good pronghorn ranges spicuous when they are alarmed. The average 15 inches (38 cm) with a mini- Reproduction, and flash of white serves as a warning sig- mum of 50% ground cover of mixed Behavior nal to other pronghorns and is visible vegetation. Healthy pronghorn popu- at long distances. lations are seldom found more than 3 Pronghorns depend on their eyesight to 4 miles (4.8 to 6.4 km) from water. and speed to escape enemies. Their Range eyes protrude in such a way that they Pronghorns sometimes migrate can see in a side direction. They prefer between their summer and winter Pronghorns currently have a scattered to live on the open plains where they ranges. Since they seldom jump over but widespread distribution through- can see for long distances. Pronghorns objects more than 3 feet (90 cm) high, out western North America (Fig. 2). are the fastest North American big most fences stop them unless they can game animal and can reach speeds of In the early 1800s, when the Lewis and go under or through them. The con- up to 60 miles per hour (96 kph). Clark expedition recorded the pres- ence of large herds of pronghorn, the total population across North America was estimated at 35 million. In less than 100 years, however, intensive 6" market hunting brought pronghorn numbers to a low of approximately 13,000. Quick action by conservation- minded leaders saved the pronghorn 38" from possible extinction.

In the late 1800s and early 1900s most 16" Great Plains state legislatures passed laws making it unlawful to kill, ensnare, or trap pronghorns. Fig. 3. Specifications for livestock fences con- Pronghorns were given complete pro- structed on antelope ranges, recommended by tection for nearly 50 years. In the 1940s the US Bureau of Land Management Regional Fencing Workshop (1974).

D-72 Pronghorns are social animals, gather- Cultural Methods other Great Plains states often charge ing in relatively large herds. In spring, $200 or more for trespass fees per Plant tall crops, such as corn, as a bar- however, bucks are alone or form hunter. Guided hunts may yield $600 rier between rangelands and small small groups. Pronghorns breed dur- to $800 or more per animal taken. In grain fields to help reduce damage. ing September and October. Bucks are addition, many landowners derive Alfalfa fields adjacent to rangeland are polygamous, collecting harems of 7 to aesthetic pleasure from observing more vulnerable and apt to suffer 10 does, which they defend from other pronghorns. Some states provide eco- damage. Pronghorns often move out bucks. Bucks and does begin breeding nomic reimbursement for crop dam- of pastures that are heavily grazed by at 15 to 16 months of age. Usually 2 age. In Wyoming, costs of pronghorn cattle to ungrazed areas. kids (young) are born 8 months after crop damage on private land, includ- mating. The kids are grayish brown at Frightening ing administration (for example, birth and usually weigh 5 to 7 pounds salaries and travel) averaged $169,453 (2.3 to 3.2 kg). Does nurse their kids Propane or acetylene exploders may per year (1987 to 1991). Similar ante- and keep them hidden until they are provide temporary relief from crop lope crop damage costs in Colorado strong enough to join the herd, usually damage. These devices are also used for the same period averaged $5,510 at 3 weeks of age. By fall, the kids can for bird damage control (see Bird per year. take care of themselves and are some- Dispersal Techniques and Supplies what difficult to distinguish from and Materials). Acknowledgments adults. Repellents Figure 1 by Charles W. Schwartz, adapted from Pronghorns are relatively disease- and Yoakum (1978) by Emily Oseas Routman. None are registered. parasite-free. Losses occur from preda- Figure 2 from Burt and Grossenheider (1976), tion, primarily coyote, and starvation adapted by Jill Sack Johnson. during severe winters with prolonged Toxicants Figure 3 from the US Bureau of Land deep snow. None are registered, and poisoning Management (1974). pronghorns also violates state laws Damage that protect them as game animals. For Additional Pronghorns sometimes cause damage Trapping Information to grain fields, alfalfa, and haystacks In areas where crop depredation and Kitchen, D. W., and B. W. O’Gara. 1982. during the winter. Damage occurs livestock competition are severe, Pronghorn. Pages 960-971 in J. A. Chapman from feeding, bedding, and trampling. and G. A. Feldhamer, eds. Wild mammals of pronghorns can be readily herded with North America: biology, management and aircraft into corral traps. After capture, economics. The Johns Hopkins Univ. Press, Legal Status they can be translocated into suitable Baltimore, Maryland. unoccupied habitat. This technique is Pronghorns have game-animal status O’Gara, B. W. 1978. Antilocapra americana. for use only by federal or state wildlife in all of the western states. Permits are Mammal. Sp. 90:1-7. agencies. required to trap or shoot pronghorns. US Bureau of Land Management. 1974. Proc. Regional Fencing Workshop. Washington, Shooting DC. 74 pp. Damage Prevention and Encourage legal hunting near agricul- Yoakum, J. D. 1978. Pronghorn. Pages 102-122 in Control Methods tural fields to help curtail crop dam- J. L. Schmidt and D. L. Gilbert, eds. Big game of North America. Wildl. Manage. Inst. and Exclusion age. Shooting permits are available in Stackpole Books, Harrisburg, Pennsylvania. some states to remove pronghorns that Yoakum, J. D., and B. W. O’Gara. 1992. Woven wire fences of 8-inch (20-cm) are causing significant damage outside mesh, 48 inches (1.2 m) high, near agri- Pronghorn antelope: ecology and of the regular hunting season. management. Wildl. Manage. Inst. (in prep). cultural fields will help to curtail dam- age. Electric fences with two wires Yoakum, J. D., and D. E. Spalinger. 1979. Economics of Damage American pronghorn antelope - articles spaced at 8 to 10 inches (20 to 25 cm) published in the Journal of Wildlife and 3 feet (90 cm) above the ground and Control Management 1937-1977. The Wildl. Soc., will discourage pronghorns from Washington, DC. 244 pp. Competition with livestock and occa- entering croplands. A single strand of sional damage to agricultural crops electric wire painted with molasses as should be weighed against the eco- an attractant and 30 to 36 inches (76 to Editors nomic value of pronghorns as game 91 cm) above the ground will discour- Scott E. Hygnstrom animals. Landowners in Texas and Robert M. Timm age pronghorn access. Gary E. Larson

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