By Joel Berger and Kim Murray Berger, biologists at the Wildlife Conservation Society’s Teton field office (THE NEW YORK TIMES, 09/08/06):
Grand Teton National Park, Wyo.
Of all the species living in the Greater Yellowstone Ecosystem of northwest Wyoming, the pronghorn is the only one native to the American West — elk, bison and even grizzly bears moved in from Asia centuries ago — but it is by no means the least exotic.
The deerlike creatures (often called American antelope, though they are not related to Old World antelope) are the fastest distance runners in the Western Hemisphere, capable of traveling 50 miles an hour. Twice a year for 6,000 years, one population of pronghorn has used that speed to travel more than 90 miles from their summer range in Grand Teton National Park to the Upper Green River basin, where they spend the winter.
In recent decades, the migration has been threatened by human development. Encroaching roads, reservoirs and ranches have closed many of the pronghorn’s routes. And the one that could conceivably remain open is being squeezed in places. Though it is a mile wide most of the way, the corridor narrows to only 650 yards at one spot and 120 yards at another. Steps need to be taken to keep this last path from shrinking any more.
Only a few hundred of Wyoming’s half a million pronghorn travel between Grand Teton and the Upper Green River basin. But unless their last route is preserved, pronghorn will no longer live in Grand Teton at all; the winter snows are too deep to allow them to stay all year.
Preserving the route should not be difficult, because 90 percent of it lies on land owned by the United States Forest Service or the Bureau of Land Management. The two agencies need only require that ranchers who pay for grazing rights keep fences at least knee-high off the ground (so that the animals can squeeze under them) and keep energy companies from setting up drilling operations in the corridor. Mining for natural gas or coal-bed methane could still be allowed, as long as wells are dug diagonally so that they come to the surface outside the edges of the corridor.
The private landowners who control the remaining 10 percent of the pronghorn corridor could be offered tax breaks in return for keeping the land passable. By setting up conservation easements, subdividing the land for housing developments could be prevented and fences on the property restricted.
Gov. Dave Freudenthal of Wyoming has already come out in support of conserving migration routes, as have many ranchers, hunters and environmentalists in the area. But Congressional action is needed to formally protect the pronghorn corridor.
All over the world, wide-ranging animals have been hemmed in by human development. Railroad lines in Central Asia restrict the migration of Mongolian gazelles; farmers’ fields block the movement of wildebeest in the Serengeti; hydroelectric dams hamper woodland caribou in Canada; and highways impede travel for North American grizzly bears.
Protecting the corridor for pronghorn would be more than a symbolic victory. It would showcase America’s commitment to conservation.