Berrendo (Sp), Gabelhornantilope (G), Antilocapre Américaine (F). Usually called antelope or pronghorn antelope in North America (or "goat" by locals), none of which is correct. The generic name Antilocapra, which means antelope-goat, is also a misnomer because the pronghorn is neither antelope nor goat in the accepted biological sense. It is the sole survivor of a large group of prehistoric spiral-horned and fork-horned ungulates that populated North America one to two million years ago. The pronghorn is a strictly North American animal. It was never in South America, and did not arrive from Asia across the land bridge that once stretched across the Bering Sea, as did most other North American game animals; it was already here.
Like the bovids, deer, chevrotains, musk deer and giraffes, the pronghorn is a ruminant or cud-chewer, a plant-eater with a four-chambered stomach, one of which (the rumen) stores undigested food that is later passed back into the mouth, where it is chewed and swallowed a second time. (Ruminants are able to take in a large quantity of rough forage in a short time, then retire to a safe hiding place to chew it thoroughly.) The pronghorn has a gall bladder. Like other ruminants, it lacks upper incisor and canine teeth, biting off its food between the lower incisors, which project more or less forward, and a hard pad on the upper gum, then grinding the cud with the premolars and molars.
DESCRIPTION (male) Shoulder height 35-40 inches (89-102 cm). Weight 100-140 pounds (45-64 kg). Females weigh about 20 percent less than males. Dental formula is i0/3, c0/1, pm3/3, m3/3 (x2) = 32.
The pronghorn is a slender, graceful animal that is a little smaller than most American deer. Its coat is long, thick, brittle and cellular. The upper parts range in color from tan to reddish-brown. The underparts, two bands under the neck, and the sides of the head are white. There is a large white rump patch of longer hairs that can be erected at will and used as a warning signal. Males have a broad, black mask from eyes to nose and black patches on each side of the neck; females lack these features. The eyes are very large-as large as those of a horse, which is commonly thought to have the largest eyes of any mammal. There are only two toes, or hoofs; the lateral toes, or false hoofs, are absent. The pronghorn is the only living North American ungulate without false hoofs.
Males, and most females, have horns consisting of a laterally flattened, unbranched, bony core that is attached to the skull and overlaid with a hard, fibrous sheath that is shed each year after the rut. The horn sheath has the same chemical basis (keratin) as hair, hoofs, nails and feathers. A new sheath develops under the old one, eventually pushing it off, and forms a short branch, or prong, roughly halfway up its length and pointing forward. The pronghorn is believed to be the only horned animal in the world that has branched horns or deciduous horns. The male's horns average about 12 inches (30 cm) in length. Females may grow very small (3-4 inches, or 76-102 mm) unpronged horns, or none at all.
BEHAVIOR Gregarious, living in small mixed groups in summer, in larger bands of as many as 100 in winter. Mates in the fall, with the young-usually one at the first birth and twins thereafter-dropping in May or June. Sexually mature at 15-16 months and fully mature at 4-5 years. Life expectancy 7-10 years.
Active at all hours, with no fixed feeding or resting periods. Both a grazer and a browser. The pronghorn does not paw through deep snow to feed, but moves to areas where wind has swept the snow away. Drinks water where available, but is able to survive on moisture from plants. Alert and wary, yet highly curious. Eyesight is truly remarkable, able to recognize moving objects at great distances. Hearing and sense of smell are very good. The fastest runner in North America, able to sprint 60 mph (97 km/h) or more, and maintain 40-50 mph (64-80 km/h) for several miles. A good horizontal leaper, but does not care to jump fences, preferring to go under or through them. A good swimmer, but avoids deep water.
HABITAT Open plains, grassland and desert scrub.
DISTRIBUTION Originally from southern Alberta, Saskatchewan and Manitoba southward to the central Mexican plateau, and from the Great Plains westward almost to the Pacific Ocean. Today, the largest population is in Wyoming, with substantial numbers also found in the states of Montana, South Dakota, Colorado, New Mexico, Idaho, Oregon, Texas, Nebraska, North Dakota, Arizona, Nevada and California, and in the Canadian provinces of Alberta and Saskatchewan. There are lesser numbers in Utah, Kansas, Oklahoma, Washington and northern Mexico. Has been introduced on the island of Lanai in Hawaii.
REMARKS The pronghorn is the least difficult North American big game animal to hunt, with the success rate near 100 percent. It does not take cover, but stays in the open plain like an African gazelle (although it is warier and stands farther off), so is not difficult to locate. To shoot just any pronghorn is not much of a challenge, but to take an old buck with large horns is another matter entirely. They may be hunted by glassing and stalking, or carefully pushed into an ambush, or sometimes it is possible to take advantage of their curiosity by tolling with a flag or other object. Long shots are the rule, and rifles should be flat-shooting, accurate and adequately scoped. Pronghorns should never be pursued with vehicles. Besides being unlawful everywhere, it is unsportsmanlike, a poor way to find a good head, and results in strongly flavored flesh. Pronghorn meat is excellent eating when the animal is cleanly shot while unstressed, skinned promptly, and cared for properly.
TAXONOMIC NOTES Five subspecies are usually listed, but their boundaries are unclear: americana (American pronghorn), from southwestern Canada and western United States; oregona (Oregon pronghorn), from eastern Washington and Oregon; mexicana (Mexican pronghorn), from southern Arizona, southwestern New Mexico, Texas and northern Mexico; peninsularis (peninsula pronghorn), from Baja California; and sonoriensis (Sonora pronghorn), from western Sonora and extreme southern Arizona. We do not separate them.
STATUS There were an estimated 35 million pronghorns in North America before Europeans arrived, but uncontrolled hunting and habitat usurpation reduced them to fewer than 20,000 by the 1920s. Subsequent conservation efforts have brought their numbers back to about one million. Today, there is controlled hunting in most of their range, with an annual harvest of about 40,000.
The subspecies peninsularis (peninsula pronghorn) is listed as critically endangered by the IUCN and as endangered by the USF&WS (1975). The subspecies sonoriensis (Sonora pronghorn) is listed as endangered by the IUCN and as endangered by the USF&WS (Arizona 1967, Mexico 1970). All pronghorns in Mexico are on Appendix I of CITES (1975). Other populations are stable and secure.