Pronghorn are native to the prairies of North America. At one time they numbered in the millions and were found on the open plains from the Mississippi River to the Rocky Mountains and from Mexico to central Canada. With the European settlement of the plains, the population was reduced nearly to extinction. In Arizona, pronghorn are found primarily in the northern plains. They also inhabit high elevation meadows between forested areas, semi-desert grasslands, and scattered herds are found in the grasslands of southeastern Arizona. The endangered Sonoran pronghorn occurs in Mexico and southwestern Arizona.
The name pronghorn comes from the pronged or sharply pointed horn of the males. The females’ horns are smaller and more slender. Pronghorn have true horns in that the horny tissue is composed of fused hairs which form over a bone core. Horns reach their maximum size during the summer and the sheaths are shed annually, usually in the fall.
Pronghorn have exceptional eyesight, often compared to high-powered binoculars, and are one of the fastest animals, being able to run in excess of 60 miles-per-hour. Despite their speed, antelope are reluctant to jump over objects, preferring to go under fences.
A conspicuous characteristic of the pronghorn is the white rump patch. When alarmed, the hair stands erect and appears as a white flash that can be seen for miles. Tan is the dominant body color, with sharply contrasting white markings on the head and neck. The top of the buck’s nose is dark and there is usually a triangular black patch below the ear. The doe does not have this black cheek patch. A short mane is present along the top of the neck. Shedding is continuous with the individual hairs being loosely attached making hides worthless as rugs. Since the hairs are hollow and can be erected at will, pronghorn are able to adjust to temperature changes.
Adult male pronghorn weigh 90 to 120 lbs. Females are about 20 lbs. lighter. Pronghorn are primarily browsers, especially on sagebrush, with grass being only a minor food source. Wild antelope usually reach ages of 6 to 8 years.
Once second only to deer as a game animal, Arizona’s pronghorn were first given a closed season in 1893. The response must have been less than satisfactory, however, as the season was completely closed in 1905. By 1922, the state’s pronghorn population was estimated to be less than 1,000 animals.
Then, for reasons that still are not fully understood, pronghorn began to make a comeback. Aided by a closed season, government predator control programs, and the abandonment of numerous homesteads, pronghorn numbers steadily increased until fears were expressed that some northern Arizona populations were in danger of exceeding their food supply. Accordingly, a limited hunt of 400 buck permits was authorized for northern Arizona in 1941.
After a closed season from 1944 to 1948, pronghorn hunting in Arizona recommenced in 1949. Hunts were liberalized gradually, until 1954 when 1,600 permits were issued and 1,146 bucks were taken. Despite the issuance of a number of doe pronghorn permits between 1961 and 1975, this level of harvest has never again been equaled. Annual harvests since 1990 have varied between 500 and 700 bucks, with archers taking a proportionally larger percent of the harvest in recent years. Plagued by encroaching subdivisions, increasing highway construction, and other land-use changes, maintaining even the present number of pronghorn is dependent on citizen involvement and an aggressive translocation program. Approximately 10 percent of the pronghorn harvest is in areas having reintroduced herds.
Pronghorn are gregarious. They are found in mixed herds most of the year; except in the spring when the bucks are alone or in small groups. In the fall, bucks collect harems up to 15-20 does, which they then defend from other bucks. Pronghorn breed in August and September and the young are born in May and June. The gestation period for the pronghorn is the longest for big-game animals in the United States. About eight months after mating, one or two fawns are born. The young are not spotted like the fawns of the deer family, but instead have markings similar to the adults. The fawns remain hidden, with the doe feeding them several times a day until they are strong enough to travel with the adults.
Breeding Period: August-September
Young Appear: May-June
Average Number of Young: 2
Distribution: 1K-8K ft, grasslands of northern and southern Arizona
Habitat: Open grass and forest parks
Food Preference: Grasses, weeds, cacti, juniper, winterfat, and chamiso
Range: 20-40 sq. miles
Live Weight: M-110lbs.; F-75lbs.
Predators: Eagle and Coyote