Antilocapra americana

Description

This "deer" has a fairly chunky body, large ears, slender legs, and a short tail. Its coat is light tan to reddish brown in color, with some white fur on the under parts, rump, sides of face, and throat. It is distinguished from other "deer" by its pronged horns, which are 12 to 15 inches long on males. These horns are further distinguished by a black horny coating that is shed every year. The horns of females are shorter and lack prongs. Pronghorn stand 35 to 41 inches at the shoulder, and weigh 100 to 140 pounds, with males being larger than females.

Distribution and Habitat

Pronghorn range from southern Alberta and southern Saskatchewan through the western United States to Baja California and western Sonora, Mexico. It inhabits open grassland and desert, where sight and running are unimpaired by woodland vegetation. Permanent water is not absolutely necessary because it can get moisture from vegetation and can go for long periods without drinking if necessary.

Reproduction

Mating takes place between July and October, with pronghorn living farther south breeding earlier than those in the north. Each buck tries to gather several mates, usually 3 or 4 but sometimes as many as 8. Does bear twins between March and May, depending on location (first-time mothers may bear only one fawn). Fawns can outrun a human at four days, can begin to eat vegetation at three weeks, and are sexually mature at 15 to 16 months.

Diet

Grasses and twigs make up the bulk of the pronghorn's diet, with some wildflowers and fruits also being taken. Specific foods vary by local conditions. Feeding is usually done in "spurts" throughout the morning and evening, with periods of rest coming between those spurts.

Social Behavior

Pronghorn are social animals. In the spring and summer, pronghorn move in small same-sex groups. Breeding-age males compete for territories, which are often bounded by physical barriers that help keep females contained. Female groups travel freely between territories. Males without territories may form into bachelor groups that wander between territories, chasing and harassing both receptive and non-receptive females. Intruding males are usually challenged by an intense "staring contest," but fighting will break out if neither animal backs down, and one or both animals may be injured during the altercation.

Conservation Status

Pronghorn once ranged from central Saskatchewan to central Mexico, and from western Iowa almost to Pacific Ocean. It is estimated that at one time some 250 million pronghorn roamed this area, but by 1908 that number had been reduced to only 20,000. Intense conservation measures, combined with range management and protection, there are now over 500,000 pronghorn in the wild. It is still considered endangered in Mexico, however, due to increasing human populations and destruction of native habitat.

Other Information

Although it is often called the "American antelope," the pronghorn is not an antelope at all. In fact, it has no close relatives anywhere in the world. The pronghorn has changed little from its ancestor, which lived between one and two million years ago.

Pronghorn can sprint for a short distance at 60 mph, and can run at 40 mph for about 2 miles, making it the fastest New World mammal.

A very curious animal, pronghorn are fond of examining at close range any unrecognized object, especially one in motion.

Although it can jump easily, a pronghorn will avoid jumping over fences or other objects unless doing so is absolutely necessary. In fact, it is fairly easy to keep pronghorn enclosed within a relatively short fence, since they will often all but starve themselves to death rather than jump across the fence to get at a plentiful food supply. They will, however, crawl under or between the wires of a barbed-wire fence if given the opportunity.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Mammalia
order Artiodactyla
family Antilocapridae
genus & species Antilocapra americana

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