The pronghorn antelope, sometimes referred to as the prairie ghost, is found only on America's Great Plains. It is the only member of its family, Antilocapridae. Smaller than the white-tailed deer, the mature buck weighs from 100 to 130 pounds and the female from 75 to 100 pounds. The male develops large pronged horns which average about 12 inches and are shed each year. The female sometimes develops smaller horns that are rarely as long as her ears. The pronghorn is extremely fast, with a top speed of about 60 miles per hour, and can easily outrun any other animal that tries to catch it. It has a large-capacity respiratory system and slender, strong legs that lack the usual dewclaws of the deer family. An antelope has large eyes that protrude from the side of its head and provide wide angle vision believed to be about the same as that of a man looking through 8-power binoculars. The pronghorn has dark brown hair on its back and sides with lighter colored hair on its belly, throat and rump patch. A male has black cheek patches, some black over his face, and black horns.
Distribution and Abundance
Fossils show the pronghorn roamed North America in its present-day form as early as the Age of Mammals, over one million years ago. Historical records indicate the pronghorn population may have numbered nearly 40 million at one time, which would have made it as abundant as bison. During the early 20th century only about 13,000 remained, but thanks to competent management there are about one million pronghorns alive today.
On the Arizona Strip, pronghorn are found on 756,000 federally managed acres in the Clayhole, Mainstreet, Hurricane, and House Rock areas. Pronghorn were native to the Arizona Strip and were reported as common by early residents. Pronghorn were apparently eliminated from the Strip in the early 1900s. They were reintroduced to the area beginning in 1961 and continue today. At present, the Clayhole pronghorn antelope population is estimated at between 250 and 290 animals. The Mainstreet - Hurricane Valley herd includes approximately 150 animals. And the House Rock Valley pronghorn population is estimated at between 100 and 130 animals. Highest densities are found in the Hat Knoll area within the Clayhole HMP area. Pronghorn were first hunted on the Arizona Strip in 1988 in Game Management Unit 12B.
The north-central rangelands on the Strip typify the area's best pronghorn habitat. Low precipitation, extremes of seasonal low and high temperatures, and harsh, windy winters characterize Pronghorn habitat on the Strip. The low rainfall of 14 inches or less, mostly occurring from April to July, results in thin vegetative cover that encourages forbs and some types of shrubby growth, rangeland that is well suited to pronghorn antelope. Open landscapes are ideal for pronghorn, a species that relies upon its keen vision to detect predators and blazing speed to outrun them.
Pronghorn habitat on the Arizona Strip is characterized by sparsely vegetated flatlands. The low hills are round-topped and the valleys are broad swales. Vegetative cover is thin with sparse stands of grasses, principally needle-and-thread, galletta, indian ricegrass, western wheatgrass, and blue grama. Prickly pear cactus is abundant. Pockets of sagebrush occur in the grasslands. A variety of forbs may be found scattered throughout the range. When conditions are right, pronghorn habitat is often covered with the orange-colored flowers of the globe mallow.
The pronghorn's highly developed social nature results in formation of aggregations ranging from small family groups to large wintering herds. Being highly mobile, the pronghorn may cover a large area during the year, especially if range conditions are less than ideal. The pronghorn's unique ability to erect patches of bristle-like stiff body hair allows it to release body heat in the hot summer, while the hollow air-filled hair insulates it against low temperatures in the winter. It also uses the erectile hair patches on its rump to signal to the herd of the possibility of approaching danger. The white hair stands out against the antelope's drab environment and signals the alarm. Some animals serve as sentinels within the herd, standing guard when the group feeds or rests.
A major portion of the pronghorn's's diet is composed of forbs and browse plants, but normally little grass. Studies from Kansas indicate that cacti made up 40 percent of the diet, forbs 36, grasses 22 and browse two percent. Wise range managers encourage pronghorns to use their rangeland to discourage the increase of undesirable plant species. Pronghorns also consume poisonous and injurious plants, including larkspur, loco weeds, rubber weed, rayless goldenrod, cockleburs, needle-and-thread grass, yucca, snakeweed, Russian thistle and saltbush.
During late summer and early fall, the bucks begin to challenge imaginary rivals. Two or more bucks may engage in mock battles, but injuries seldom occur. As the height of courtship and mating approaches in September and October, females in the harem become more and more attentive to the bucks.
Pronghorns have been known to breed as fawns but they usually breed for the first time when they are 16 to 17 months of age. The does usually produces twin fawns in early June after a gestation period of about 250 days. Fawn production has been as high as 48 fawns per 100 does on the Arizona Strip, but typically ranges from 20 to 35 per 100 does. Fawns are usually born in swales and low-lying areas with small ridges or hills surrounding them where the vegetation is short and sparse. At birth a fawn weighs between five and nine pounds.
The greatest losses occur during the first two months of life. Only about 40 percent of the fawns born in June live until mid-July. Coyote control can improve fawn survival, but it is not economically practical on a large scale. In a few areas bobcats are important predators and in areas close to bluffs golden eagles kill and feed on fawns. Adult mortality probably averages about 10 percent annually, but exceptional circumstances such as a severe winter can be devastating.
Wildlife is a renewable resource and if managed wisely, can be cropped annually without depleting the stock. On this premise the resource is managed to provide the greatest number of pronghorn and recreational benefits to hunters while keeping numbers at levels consistent with the needs of other resource uses. Information on population, production, harvest and general health of the herd is incorporated into annual management recommendations developed by the Arizona Game and Fish Department.
During the 36 years since 1953 (the 1958 season was closed) 39,018 rifle hunters harvested 30,963 pronghorns for an average hunter success of 81 percent. Due to the low pronghorn's population in 1989, the only unit open to hunting was the Commissioners authorized the issuance of only 50 buck-only permits. The number of antelope increased in 1990 and 100 hunting permits were issued, and as the herd continued to grow, that number increased to 325 Permits in 1991.
Techniques and strategies for hunting pronghorns vary with individual hunters and field conditions. Pre-season shooting practice and scouting the area to study the habits of individual herds are strongly recommended. Distances can be deceptive in the open space. Antelope hunting requires discipline, patience, experience and knowledge of the species. The hunter should quietly and carefully approach as close to the antelope as possible, or until he is certain a clean, one-shot kill can be made.
When field dressing an antelope take special pains to prevent paunch material or hair from contaminating the meat, as much of the wild or gamey flavor attributed to antelope or other game is the result of careless handling. Bacterial growth and decay of meat depends on warmth and moisture, so it is important to cool and dry the carcass as soon as possible. Memories that will last a lifetime, many meals of delicious antelope meat, and a beautiful mount for the den are rewards of the hunt.