Antilocapra americana
(Ord, 1818)

an-ti-lO-cap-ra a-mer-e-cA-na

An adult male Prognhorn.

The Pronghorn readily can be distinguished from all other mammals in Kansas. It is smaller than deer, and its pelage is pale cinnamon-brown or tan with black or dark brown markings around the edges and tips of the ears, over the eyes, at the angles of the jaw, and around the muzzle. It has pale or white patches on the cheeks, neck, and underbelly and two white patches of erectile hair (about 75 mm long) across its rump. The supraorbital horns in males are forked or "pronged" anteriorly, while those of females (if present) are smaller and seldom have prongs. Both sexes shed the horn sheath annually, males about a month after rut but females at no specific time. The pelage features coarse, brittle hair containing air cells which insulate the animal from winter winds.

The Pronghorn is a denizen of arid and semiarid areas of western North America. It occurred in the western three quarters of Kansas before the arrival of settlers from Europe. The eastern limit of the Flint Hills was probably its eastern boundary at the time. It was extremely abundant in Kansas in early historic time but declined precipitously after settlement of the region. It never was completely extirpated in western counties of Kansas because small herds wandered back and forth between Kansas and adjacent states. Beginning in 1964, pronghorns were reintroduced to supplement these small herds. These reintroductions generally were successful, and pronghorns now can be found in several areas of western and central Kansas.
Three genera of pronghorns are known from the Miocene. Their evolutionary precursor is not known, but it is assume to be a primitive bovid stock. By the Pliocene and Pleistocene, 12 genera of pronghorns occurred in western North America and one genus was known from Florida. Antilocapra is sole surviving genus the of this once diverse lineage.

(, Museum Voucher) (, Observation) (, Literature Record)
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  • Occurrence Summary:  
  • 52 Total Records 
  • 33 Museum Vouchers 
  • 19 Other Observations 
Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Barton (1); Chase (1); Comanche (1); Edwards (6); Ellsworth (1); Gove (2); Greeley (1); Hamilton (1); Logan (6); Meade (5); Morton (9); Norton (1); Reno (3); Rice (1); Rooks (2); Rush (1); Trego (2); Unknown (2); Wallace (5);

Natural History:
The Pronghorn eludes its enemies by fleetness of foot. It has been clocked at 95 km per hour for short distances and can cruise at 48 km per hour for for as much as 7 miles. Usually they do not jump over obstacles and, when barbed-wire fences block their path, they crawl or slide under the bottom strand, often very rapidly. When frightened the long white hair is raised on the rump patch and "flashes" in the sunlight. Even young fawns can race along with adults. During summer, pronghorns disperse, browsing and sunning in small loosely formed bands. Does form groups of up to a dozen; they usually wander away from the band to give birth, and then rejoin it a few weeks later with their fawns. Young bucks form slightly larger "bachelor" herds, and in good habitat adult males stake out territories which they defend all summer against other bucks. With the onset of the rut in late summer, territorial bucks try to "hold" does within the confines of their territories and, when females become receptive, mating occurs there. In poorer habitat, territories may not be defended. Non-territorial bucks also court does, often in groups, and the does often flee from this harassment to the territory of an older male. After the rut, males cast their horn sheaths, abandon their territories, and join other males, females, and fawns in large winter herds. Long movements (100 km or more) may take place at this time from summer to winter range. They shelter below cut banks and down in ravines to avoid cold winds. They are curious animals, and will flee to a ridge top when frightened, then pause and look back. 

Adults may attain the following dimensions: total length 1245-1472 mm; tail 89-178 mm; hind foot 390-430 mm; ear 142-149 mm; weigh 47-70 kilograms. 

Pronghorns in Kansas feed largely on forbs in late spring, summer, and early autumn, on forbs supplemented with dicots in late autumn and early spring, and on dicots in winter. The dicot most commonly eaten in areas that lack sagebrush is winter wheat. In fact, pronghorns are able to live and reproduce where 30% of the land is used for cultivated crops at least in part because they are able to use those crops as food during months when native foods are in short supply. 

Healthy adult pronghorns can elude most predators, but coyotes routinely prey on newborn animals and sick or injured individuals.
Pronghorns are polygamous. Females typically become sexually mature at about 16 months of age, but some individuals conceive as early as 5 months of age. The breeding season in Kansas usually lasts through September. Gestation in captivity averages 252 days. Twins are more common than single young, being born in Late May or early June. New-born fawns weigh about 3 kg. They remain hidden for about 6 days, during which time the doe returns to nurse each twin. When they are about one week old, the fawns begin moving about with their mother. Frequency of nursing declines during summer, and the growing fawns eat more and more vegetation, until, with the onset of the breeding season in September, they are fully weaned.

Occurrence Activity:
Five subspecies of pronghorns currently are recognized. The subspecies on the Great Plains is Antilocapra americana americana

1925 Nelson, E. W. Status of the pronghorned antelope, 1922-1924 U. S. Dept. Agric. Bull. 1346():1-64
1978 O'Gara, B. W. Antilocapra americana Mammalian Species 90():1-7
1981 Sexson, M. L., and J. R. Choate Diet of pronghorn in western Kansas Journal of Range Management 34(6):489-493
1981 Sexson, M. L., and J. R. Choate Historical biogeography of the pronghorn in Kansas Transactions of the Kansas Academy of Sciences 84(3):128-133
1987 Choate, J. R. Post-settlement history of mammals in western Kansas Southwestern Naturalist 32(2):157-168
2008 Timm, R. M., G. R. Pisani, J. R. Choate, N. A. Slade, G. A. Kaufman, and D. W. Kaufman, . pp.
Account Last Updated:
11/19/2019 12:29:33 PM

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