Pronghorn

Common Name: Pronghorn
Class: Mammalia
Order: Artiodactyla
Family: Antilocapridae
Genus: Antilocapra
Species: Antilocapra americana
Pronghorn Taxonomy/Description


photo M. Noonan

Often called the prongbuck or pronghorn antelope, the pronghorn is neither a deer nor an antelope. Its scientific name, Antilocapra americana, means “American antelope goat”, But this title is also a misnomer, for pronghorn are not goats either. Pronghorn are members of the Artiodactyla order of mammals. It should be noted that pronghorn are classified in their own separate family, Antilocapridae. Pronghorn’s special taxonomic categorization is mainly due to their peculiar horns. True horns are permanent, unbranched structures consisting of a bony core surrounded by a durable keratin sheath. A pronghorn’s keratin sheath, however, is shed annually. Pronghorn are the only living species that shed the outer coating of their horns in this way. A few female pronghorn also have horns, but this is not typical.


photo M. Noonan

Pronghorn have tan bodies with noticeable white markings on their neck, underside, and rump. Males have black face marks, present beneath their chin, atop their snout, and behind the ears. Large protruding eyes provide pronghorn with a 360 field of vision, and long, black eyelashes act as sun-visors. Male and female pronghorn each have scent glands, which are important for communication and courtship. Both sexes have glands located between the toes and on the rump, but males have ear and tail glands as well. Alarm odors are produced by the rump glands, and ear glands of males are used to mark territories. There are five subspecies of pronghorn, slightly differing in color, size and build. The northern forms (Oregon and American) are located throughout the northwestern American prairie, with desert scrubland forms located in the southwestern American and Mexican deserts (Sonoran, Mexican, and Peninsular).

Pronghorn Habitat/Diet

Pronghorn roam the wide, open ranges of the North American prairie and desert. Habitat types include grasslands, brushlands, and desert scrublands. Due to their extensive habitat type as well as seasonal change, pronghorn eat a variety of flora. Their teeth are adapted for this selective grazing, growing continually. Their diet consists of cactus, grass, browse, and forbs (herbs other than grass). Shrubs are eaten all year round, with grasses used primarily in the spring, and forbs, which are important for healthy fawning, are eaten during the late fall. Pronghorn also ingest several noxious weeds, making them important for range management.


photo M. Noonan

Pronghorn Behavior/Reproduction

Pronghorn have adapted to the open plains by developing extremely keen eyesight. Its large, protruding eyes can detect movement up to 4 miles away. This exceptional vision is used to spot approaching predators and warning signals from other pronghorn over long distances. When an immediate threat is present, pronghorn escape with great speed. Reaching speeds of 60 miles per hour (mph), pronghorn are the fastest animals in the western hemisphere. On the world scale, pronghorn are only bested by the African cheetah, which are said to attains sprints of 70mph. Pronghorn are very 'curious'. They will approach and inspect moving objects, even predators, from long distances. This 'curiosity' was exploited by early settlers, whom attracted pronghorn within gunshot range by waving cloth rags attached to poles. This tactic, called 'flagging', is now illegal.


photo M. Noonan

The pronghorn’s breeding peak occurs between mid-September and early October. Their average gestation length is 252 days.

Pronghorn History

The size of the pronghorn population prior to the European settlement of North America was about 35 million. Their range extended from eastern Washington and southern Manitoba, to Baja California and northeastern Mexico. A 1920 count estimated that fewer than 20,000 animals remained. A population of 500,000 animals is currently estimated to exist throughout the United States, Canada, and Mexico.


photo M. Noonan

Our Experience with Pronghorn

A group of pronghorn was first observed from our van, grazing in the vast expanse of prairie along a backdrop of a vibrant, setting sun. We quickly exited; glimpsing the pronghorn as they gracefully took flight, by foot.


photo M. Noonan

Pronghorn Conservation

Estimated to once have numbered in the millions, the pronghorn populations had fallen to 20,000 by the early 1900s. Since then, conservation efforts have aided pronghorn in making an astounding comeback, and the current population is estimated at about 1 million individuals. This comeback is partly due to a growing human awareness of pronghorn behavior. Pronghorn do not jump fences but instead will choose to crawl beneath them. Unfortunately many pronghorn became entangled this way, often leading to injury or death. To deal with the pronghorn’s difficulty in overcoming fences, strategic placement of modified fence sections is now common and this allows most pronghorn to pass through prairie ranches. In many ways, this species can be counted as a conservation success story. Wildlife advocates, ranchers and government agencies all cooperated in adapting human practices to allow this wonderful species to co-exist with our activities in its habitat.

 

Glossary:

Artiodactyla – Mammalian Order, meaning "even toed", which consists of all even-toed hoofed mammals, including families that contain cattle, antelope, deer, camels, and hippopotamuses

keratin – chief structural protein of hair, nails, and horns
 

Content provided by Canisius College students under the direction of Michael Noonan, PhD.