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Pronghorns in the Horse Heaven Hills.More of Denny Granstrand's photos can be found at www.granstrand.net/gallery/ (Photo courtesy Denny Granstrand)

A small population of pronghorns were native in eastern Washington, hanging on despite hunting and habitat changes until the early 1900s. Efforts to reintroduce this mammal by the Yakama Nation, the Central Washington Chapter of Safari Club International, many volunteers in south-central Washington, and the Colville Confederated Tribes to the north began about 2010. Now, more than 250 roam the shrub-steppe in south-central Washington, most on the Yakama Nation lands. Their numbers are slowly increasing, indicating this may be a successful reintroduction program. Future management of the population may be undertaken by the Yakama Nation and Washington Department of Fish and Wildlife as the need arises. As of now, there is no hunting of pronghorns in Washington.

How to spot one: Pronghorns are small ungulates about three feet high at the shoulder, with a large head and huge eyes (as large as a horse!). Female or young with smaller or no horns may superficially resemble a pale tan deer though with white bands on its throat, rump, and lower sides. A mature male, on the other hand, is unmistakable with a black band on its face and curved horns reaching 20 inches long, which have a bony core covered by a sheath of agglutinated hair; this sheath shed after rutting.

These horns sport a single prong projecting forward on each horn, hence the name pronghorn. If seen running, there is no mistaking pronghorns for deer as they race across their open country habitat at speeds up to 50 miles per hour, the fastest of any North American mammal.

When and where to look: In south-central Washington, pronghorns range through shrub-steppe habitats in Horse Heaven Hills on the Yakama Indian Reservation mainly east of US-97. Smaller numbers roam these ridges outside the Yakama Nation lands in the mosaic of dryland wheat and fragmented shrub-steppe of eastern Yakima and Benton Counties.

Shrub-steppe areas in Klickitat County also have small numbers. In north-central parts of the state, shrub-steppe on the Waterville Plateau was core habitat until swept by fire in September 2020, eliminating much habitat, putting this population in jeopardy.

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Chow time: Forbs, such as clovers, wild onion, locoweed, lupines, and larkspur make up about two-thirds of a pronghorn’s diet. A little more than a quarter of their diet is woody browse from shrubs such as sagebrush and rabbitbrush. In early spring, fresh grasses such as wheatgrass and even cheatgrass is relished.

Home life: Pronghorns are most active at dawn and dusk and usually occur in small bands. They begin breeding at about 1 ½ years when males may collect small harems with mating occurring from August through October. After a gestation period of 230 to 240 days, the young are born. The kids are grayish-brown at first and left alone by their mother for a few days except while nursing. They are then able to follow her.

Our pronghorns are the sole survivor of a family of many species of antelope-like mammals (though not true antelopes) that ranged the prairies and open country in the past, from 15 to one or so million years ago. The reasons for their die-off are not well understood, but they are members of a cast of big mammals (mammoths, saber-tooth cats, and others) that became extinct towards the end of the Ice Age.

Wildlife Moment, focusing on native wildlife, typically runs in Outdoors on the first Thursday of the month, with the cooperation of the Yakima Valley Aububon Society.