RIVERTON -- New research on the antelope migration corridor between the Grand Tetons, through the Upper Green River to the Red Desert, suggests that the timing of energy development activities could save one of the great migration corridors of the world.

Joel Berger of the Wildlife Conservation Society briefed board members of the Wyoming Wildlife and Natural Resources Trust last week about his research into the winter corridor stretching 400 miles from the Grand Tetons to the Rock Springs area.

Berger, Kim Murray Berger and Jon Beckmann were commissioned by several energy companies and the Wyoming Game & Fish Department to study antelope in the Upper Green.

He mapped the corridor using global positioning system (GPS) collars and learned that there really are no alternative corridors that can be used.

Berger also found that the corridor is extremely narrow in spots, with three critical bottlenecks running north to south:

* The Red Hills area southeast of the Grand Tetons and northeast of Jackson, which is less than 200 yards wide.

* The Funnel (about 120 yards wide) about 25 miles north of the third bottleneck.

* While many people have heard of the Trappers Point bottleneck Berger said, all three are critical threats to the annual migration.

“We often hear the expression that an animal will find a way,” Berger said.

That isn’t really true, given the fact that 75 percent of the region’s migration corridors are now blocked, he said. Based on 11,000 data points, Berger and other biologists know with great certainty that the Upper Green migration corridor still works, but is threatened by energy and residential development.

Berger said the world has lost many migration corridors for large mammals, and that the Upper Green migration is the largest and second-longest left in North America.

Berger's research established that antelope migrating in the fall, down from the Grand Tetons area, take only three days to move the 90 miles down to Pinedale, where they disperse further to the foothills of the Wyoming Mountains or south into the Red Desert.

He implied that if development activity could halt or be minimal during those three days, the antelope herd would be able to successfully migrate south without undue stress and interference.

Berger said the return migration in the spring takes a little longer n one to two months n based on his GPS data sets, with most of the migration within one month.

“I’ve seen 20 antelope in a line, so I’ve seen this migration.” said Delaine Roberts, chairman of the Trust's board of directors. Berger said the Jackson-area herd numbers about 200, with a slightly larger group from the Union Pass area joining in the migration. All told, up to 500 animals take part in the migration.

“Why should we worry about these animals?” asked Berger. Because Wyoming and the West need a success story n something preserved in spite of rapid energy development, he added.

What’s needed is wildlife-friendly fencing through the corridor, which has been successfully implemented in the Funnel neighborhood, he said.

Louise Lasley, director of the migration corridor initiative for the Wildlife Conservation Society, said there are 40 more private property owners between the Funnel and Trapper’s Point. To date, private property owners have been more than amenable to protecting the corridor, she said, on a voluntary basis.

In addition to wildlife-friendly fencing and reducing human activity around the corridor during migrations, Berger suggested placing signs, educating the public and creating incentives for the property owners along the corridor, to keep the corridor open.

Berger said livestock operations, ATV use and even hunting are non- issues along the corridor, because they don’t affect the movement of the antelope.

Meredith Taylor, a representative of Wyoming Outdoor Council, urged trust board members to provide funding to protect the corridor.

Berger also addressed the habitat fragmentation issue, noting that while antelope do habituate to human presence when not hunted or harassed, the ever continual fracturing of previously undisturbed lands leads to reduced usage and ultimate abandonment of habitat.

Indeed, none of the GPS-collared animals used the Jonah Field last winter, where large-scale natural gas drilling has been proposed.

According the research by Berger’s team, pronghorn generally shunned concentrated gas fields, and there was no evidence that the animals used those areas at night when human disturbance was reduced.

Berger told the trust board that the probability of antelope using a 40-acre fragment was less than 2 percent; that use of a 100-acre fragment was 6.7 percent. However, Bergersaid, occupancy probability increases to 49.2 percent on 600-acre fragments and 70.8 percent on fragments of 1,000 acres or larger. This has profound implications for the density of energy development, he said.

Brodie Farquhar is a freelance writer based in Lander. He can be reached at brodiefarquhar@hotmail.com