Feds plan new endangered pronghorn site in western Arizona’s Kofa National Wildlife Refuge

New endangered pronghorn site eyed in Arizona

PHOENIX — Federal wildlife officials plan to move a handful of endangered Sonoran pronghorns to the Kofa National Wildlife Refuge in western Arizona next winter in hopes of establishing a new population of the rare animals.

The proposal by the U.S. Fish and Wildlife Service is part of an effort to bring back a thriving population of the antelope-like creature. Only about 70 to 90 of the animals now live in the wild in the U.S., mostly in the Cabeza Prieta National Wildlife Refuge about 130 miles west of Tucson and the adjacent Barry M. Goldwater Range and Organ Pipe Cactus National Monument. Another 40 or so are in a captive breeding program, and about 400 live in northern Mexico.

The formal proposal by Fish and Wildlife was published in the Federal Register last week. The plan envisions releasing about a dozen captive-bred pronghorns at the Kofa refuge in Yuma County next winter and up to 20 a year thereafter. Another group would later be reintroduced southeast of Gila Bend.

The service is also proposing that the new population be designated as “experimental,” releasing the government from some of the most onerous provisions of the Endangered Species Act for those animals.

Sonoran pronghorns are North America’s fastest animals. They used to roam freely across the U.S.-Mexico border in the Sonoran desert in search of feed and water.

Pressure from ranching and development, and roads such as Interstate 8 and Mexico’s Highway 2 cut them off from much of their normal migratory range, said Jim Atkinson, a federal wildlife biologist who works on the pronghorn recovery program. That included seasonal watering areas north and east of the refuge.

The pronghorn’s numbers slowly dwindled, and by 2001, only about 140 remained in the U.S. Then a drought decimated the species, cutting its population to just 21 in 2002.

“We were about three weeks away from losing all the animals in the U.S. if it hadn’t rained when it did,” Atkinson said Tuesday.

Since then, biologists have nursed the population back using a breeding program, supplemental watering holes and a plan to supplement feed with alfalfa in case of another drought. Atkinson said efforts to feed alfalfa to pronghorns in the earlier drought failed because the animals didn’t recognize it as food, but released captive-raised animals now do, and they will teach others.

The idea of establishing a new area for pronghorns has been around for years, and formal planning began about three years ago. A series of public meetings are planned before the proposal is formally adopted.

Even if the proposed new population takes hold, the animals on the historic range will remain under pressure from a combination of environmental and human factors. The biggest ongoing problem is smugglers and illegal immigrants, and the Border Patrol agents who chase them, Atkinson said.

The animals are easily spooked, and a herd will move large distances if border agents or smugglers approach, something that is especially bad during spring fawning season.

“If the herd has to suddenly move 10 or 15 miles because of some disturbance, there’s a good chance the fawns won’t survive,” Atkinson said. “Try as we may with coordination (with the Border Patrol), the specific situation with the border traffic pretty much defines the actions they have to take.”

On the Net:

U.S. Fish and Wildlife Service, Arizona: www.fws.gov/southwest/es/arizona