New state guidelines adopted in Wyoming, an energy-rich state that constantly seeks to balance conservation with development of fossil fuels, seek to protect some of North America's longest wildlife-migration routes from oil and natural gas drilling on public lands.
The guidelines approved Thursday by the state Game and Fish Commission call on state wildlife officials to continue to identify routes traveled twice a year by thousands of elk, antelope and mule deer. Tracking technology has enabled scientists in Wyoming and elsewhere to map such routes with increasing precision—and even discover new ones.
Biologists also will study how to counter threats to migrations, such as by replacing barbed-wire fences with a type that allows antelope to crawl under the bottom wire.
Options could also include prohibiting oil and gas development in especially sensitive areas along migration corridors, a point of contention between environmentalists and the petroleum industry.
"The science is clear that the best way to ensure long-term persistence of migration corridors is to prohibit development," said Julia Stuble with the Wyoming Outdoor Council.
But the guidelines in no way would require Wyoming to prohibit oil and gas exploration, pointed out Esther Wagner, vice president of the Petroleum Association of Wyoming.
"They're just recommendations," Wagner said. "They're not regulations."
The guidelines will come into play when petroleum developers seek to drill on federal land in Wyoming. State biologists will refer to their findings and the guidelines when they advise federal agencies on wildlife populations on federal land, which they do regularly.
Wyoming officials often find themselves caught between encouraging fossil fuel development and protecting wildlife habitat. In this case, migrating ungulates—a class of hooved animals that includes moose and bison as well as elk, mule deer and antelope—are popular to hunt.
Similar challenges confront wildlife managers in energy-rich Montana and Colorado.
"We're not going to shut the lights out. We're not going back into the stone age. And we're not going to let wildlife decline," Game and Fish Commissioner David Rael said.
In western Wyoming, vast natural gas reserves underlie habitat for elk, antelope and mule deer that travel into the Yellowstone Ecosystem each summer.
Scientists in the region recently documented the longest known mule deer migration. A group of mule deer travels between the Gros Ventre Range in summer to the Red Desert in winter, a distance of 150 miles each way.
A group of antelope travels between Grand Teton National Park in summer and the Upper Green River Basin in winter, covering more than 100 miles each way.
Of particular concern are areas called bottlenecks where surrounding mountains, lakes or human development have pinched migration corridors to a mile wide or less. Biologists also suggest paying close attention to areas along migration corridors where wildlife stop to rest and eat.
Mule deer especially have suffered from the loss of habitat in Wyoming. Their numbers are down 40 percent over the past 20 years, according to the state Game and Fish Department.
Wyoming, population 584,000, remains the nation's least-populated state. But road construction and home development also get in the way of migrating wildlife. The state in recent years has countered that by building overpasses and underpasses where migration routes cross highways.
Herds of migrating antelope that used to congregate along roads in a frenzy can now continue on their way without too much fuss, commission President Charles Price said.
"It's not a panicked crossing," Price said. "It's a rapid crossing. They don't like to stand up there."
Explore further: New mapping project details big game migrations in Wyoming wilderness