When Americans think of the Wild West, we often conjure cowboys and ranchlands, grizzly bears and mountains, or a great plain where the buffalo once roamed. But Dr. Joel Berger, senior scientist with the Wildlife Conservation Society's North America Program, thinks of pronghorn. As the fastest land animal in North America, these lithe antelope migrate annually across tremendous distances, at speeds of up to 55 miles per hour.

Given the significant size of the pronghorn population-which numbers almost half a million in Wyoming alone-their plight has not inspired great sympathy. But this distinctly American species has become a casualty of one of the most provocative issues of our time: the national energy crisis. As Western lands become increasingly subject to development, the conservation of Rocky Mountain wildlife is losing ground-literally.

Berger and his team in the WCS Teton Field Office, which includes researchers Dr. Kim Murray Berger and Dr. Jon Beckmann, are working on two projects to carve out a home for pronghorn in the face of the impending human footprint. One is the creation of a permanently protected migration corridor for the antelope. This ambitious project would conserve the most extensive trail of its kind in the Western Hemisphere, and one that has been in use since the end of the last Ice Age. The scientists' other project is a study on how natural gas development in the Rockies influences the pronghorn that winter there. Shell Exploration & Production Company, Ultra Resources, Inc., and other energy groups are funding this five-year investigation, an important collaboration between the industry and conservation sectors.

During a break from his work in the mountains, valleys, and sagebrush-dominated plains of Wyoming, Berger spoke about these magnificent migrants and what it will take to keep alive the Wild West.

Why is North America's fastest land animal relatively unfamiliar? Does the pronghorn's lack of renown make its conservation a challenge?

Bears and wolves garner disproportionate attention in the eyes of the public because carnivores are rare in number relative to prey species. Pronghorn are not an endangered species, and even though they are the only hoofed mammals to have evolved in North America, they fail to stir the imagination. They should. They once occurred with cheetahs and lions here, just as gazelles and zebras still do in Africa.

What is the range of the pronghorn, and does it differ today from what it was before the American westward expansion?

Pronghorn are primarily a species of grasslands and deserts. They occur in all western states and several Canadian provinces and Mexican states. Their population sizes have been reduced some 95% since the 1800s, but their overall distribution remains generally similar to what it once was.

Describe the spectacle of the pronghorn migration.
During the fall migration, the animals move 30 miles a day for three or four straight days. They rarely feed, and basically stream across the landscape. Like caribou, they travel in small groups that number anywhere from a few to 20­-30 animals. In the spring, the pronghorn move northward at a slower pace, as they follow the receding snowline. This means the journey commonly takes a month or longer. What impresses me about the long-distance trek is not the number of animals per se-for they do not move by the thousands like wildebeest or caribou-but the terrain that is covered: high mountain passes, swollen, snow-fed rivers, and canyons and river corridors.

Why do pronghorn travel so far?
We're not terribly sure what motivates pronghorn to undertake extensive migrations. Contrary to what you might assume, these movements do not necessarily bring animals to better grazing areas or regions where predator densities are lower.

Wouldn't a corridor impose unnatural restrictions on the migration path?
Our vision for a protected corridor is on the order of 90 miles long and 1.2 miles wide-the distance the pronghorn cover as they bounce along a "path" that is just over a mile wide. Areas on either side of this path are forested or riverine and are not generally used by the animals as they move between summer and winter home ranges. Parts of this route have been used for 6,000 years, which makes it important both culturally and biologically.

What are the challenges you face in setting up this corridor?
The public has been receptive to the idea of corridor protection, and support for it is generally stronger the farther one lives from the gas fields. But public support for federal protection is complicated by Wyomingites' general distrust of the federal government. And since the state lacks statutory authority to manage these federal lands, the stalemate is real. The only real loser is the pronghorn-a species that has no arch enemies because it does not compete with cattle, or carry diseases threatening to other wildlife or livestock, or consume livestock as do bears and wolves upon occasion.

How have gas fields changed the landscape since you began working in Wyoming?
The gas field proliferation in Wyoming has been daunting. In just five years, there has been more than a tenfold increase in traffic in areas where pronghorn winter. To put this in perspective, can you imagine morning commuters in any area of the U.S. facing that kind of gridlock? We've seen up to six animals splattered on the road, all killed by a single vehicle. The habitat is being degraded and fragmented, and animals are starting to avoid areas they formerly relied on to make it through the winter. I understand our nation's need for energy, yet I also know a number of Americans have made massive commitments to protecting wildlife, and these are often ignored.

How does this kind of development impact other regional wildlife species?
The effects of development are not well understood or documented. However, the three species of greatest concern in areas near the expanding gas fields of western Wyoming-mule deer, sage grouse, and pronghorn-are all facing reduced access to habitat. In reality, the issue is whether the resulting shift in their movements causes a decline in the population. These possible effects are never immediate but they tend to show up after years and years, at which point the population dies off.

What are the outcomes you hope will result from the energy development study?
We would like to see our research create relationships between energy development and wildlife conservation. Eventhough our study is being conducted in Wyoming, lands from Canada to Mexico are still home to wildlife, and have multiple uses. If we can understand wildlife needs, then perhaps the knowledge can be applied to other areas where balanced land use is still possible.



Posted by: Kelly    Source