Pronghorn antelope

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 tail 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 dew claws 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.

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. Antelope occur primarily in the western half of the state.

A pronghorn depends on its vision to alert it to danger and its speed to outrun predators and to survive in the open landscape.  Low precipitation, extremes of seasonal low and high temperatures, and windy, harsh winters characterize the Great Plains and Basins area.

The pronghorn's highly developed social nature results in it being found in small family groups to large wintering herds. Being highly mobile, the pronghorn may cover a large area during the year when the range is poor. The antelope's unique ability to erect patches of its bristle like stiff body hair allows it to release body heat in the hot summer, while the hollow air filled hair insulates it against the lower
temperatures in the winter. It also uses the erectile hair patches on its rump to signal to the herd the possibility of approaching danger. The white hair stands out vividly against the antelope's drab environment and signals the alarm. There seem to be sentinels within the herd that stand guard when the group feeds or rests, much like other herd or flock type animals. A major portion of the pronghorns' diet is composed of forbs and browse plants, but normally little grass. Wise range managers encourage pronghorns to use their range land to discourage the increase of undesirable plant species. Pronghorns also consume poisonous and injurious plants.

During late summer and early fall, the bucks begin to challenge imaginary rivals, or 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.  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.  Most of the loss of fawns is due to coyote predation. Coyote control can improve fawn survival, but it is not economically practical on a large scale. In a some areas bobcats also feed on fawns.