Pronghorn Antelope - Wildlife Damage Management

Range

Figure 2. Range of the pronghorn in North America.

Pronghorns currently have a scattered but widespread distribution throughout western North America (Fig. 2). In the early 1800s, when the Lewis and Clark expedition recorded the presence of large herds of pronghorn, the total population across North America was estimated at 35 million. In less than 100 years, however, intensive market hunting brought pronghorn numbers to a low of approximately 13,000. Quick action by conservation-minded leaders saved the pronghorn from possible extinction.

In the late 1800s and early 1900s most Great Plains state legislatures passed laws making it unlawful to kill, ensnare, or trap pronghorns.

Pronghorns were given complete protection for nearly 50 years. In the 1940s and 1950s, limited hunting seasons were permitted, and pronghorn sea-sons have been held ever since in most Great Plains states. Populations have shown a notable increase in the last 2 decades.

A game management success story documents an increase from a population low of a few bands of pronghorn in Nebraska during the early 1900s to a current population of about 7,000. Trapping and transplanting programs to reestablish pronghorn populations by the state wildlife agencies and proper management and protection have been major factors in the pronghorn’s recovery.

Habitat

Pronghorns thrive in short and mixed grasslands and sagebrush grasslands. They prefer rolling, open, expansive terrain at elevations of 3,000 to 6,000 feet (900 to 1,800 m), with highest population densities in areas receiving an average of 10 to 15 inches (25 to 38 cm) of precipitation annually. Vegetation heights on good pronghorn ranges average 15 inches (38 cm) with a minimum of 50% ground cover of mixed vegetation. Healthy pronghorn populations are seldom found more than 3 to 4 miles (4.8 to 6.4 km) from water.

Figure 3. Specifications for livestock fences constructed on antelope ranges, recommended by the US Bureau of Land Management Regional Fencing Workshop (1974).

Pronghorns sometimes migrate between their summer and winter ranges. Since they seldom jump over objects more than 3 feet (90 cm) high, most fences stop them unless they can go under or through them. The construction of many highways with parallel fencing has greatly altered the migratory patterns of pronghorns. Woven wire fences, in particular, are a barrier that impede pronghorn movements to water, wintering grounds, and essential forage. Proper spacing of barbed wire in fences (Fig. 3) is essential to allow adequate pronghorn movement.

Food Habits

Pronghorns eat a variety of plants, mostly forbs and browse. Sagebrush often makes up a large part of their diet. They are dainty feeders, plucking only the tender, green shoots. Pronghorns compete with sheep for forbs, but are often found on summer cattle ranges where cattle eat the grasses, leaving the forbs and browse. Dietary overlap of pronghorns with sheep and cattle was 40% and 15%, respectively, in New Mexico. In the winter, pronghorns often feed in winter wheat and alfalfa fields.

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