On the Edge
Wolverines, long admired for their ferocity and canniness, are so elusive that few people have even seen one. Now biologists are racing to find them before trappers do.
Wolverines require enormous chunks of territory and travel amazing distances looking for food and mates. Using a GPS collar, Inman documented a dispersing male wolverine, M304, traveling 256 miles in 19 days. Then, after a few days' pause, M304 rambled 140 miles in seven days--straight-line measurements that do not account for the jagged terrain he actually traversed. In the 34 months he was monitored before being killed by a trapper, M304 appeared in eight distinct mountain ranges, in three states, two national parks, and three national forests.
But Inman suspects incursions into the high country by snowmobilers, heli-ski operations--where skiers access remote areas via helicopter--and back-country cross-country skiers may have impacts on wolverine populations. Wolverine territory is remarkably short on food--an avalanche-killed mountain goat here, a starved-to-death bighorn there--which probably influences the animal's slow reproductive rate.
"They exist at the margins of what's possible," Inman says. "Anything that could change that energetic balance would have serious repercussions for an animal that reproduces so slowly."
One of Inman's radio-collared females lives in an isolated area of the Madison Range that's nearly overrun with snow-mobiles in winter. She happens to be one of the smallest animals in Inman's study, at one time weighing only 14 pounds when she was captured. While Inman acknowledges that he has not yet compiled the statistical power to de-
finitively prove that winter recreation is harming wolverines, he says the case of the 14-pound female is "intriguing."
"If there's a problem with people snowmobiling and recreating, if wolverines are staying away from areas where these people are because they don't want to encounter human activity, is that enough to tip the energy balance?" Inman asks.
It's just one of the questions he and his crew of dedicated, sore-legged associates are trying to answer. Like many scarce animals in this country, wolverines adapted to fit a niche defined by inhospitable terrain and food scarcity.
We, meanwhile, don't know whether we blithely knock loose their claw holds on survival in the name of fun. The desires of a relatively few people--snowmobilers, heli-skiers, recreational trappers--to romp around in a way they see fit may push the wolverine over its last brink before we even know enough about the species to imagine what could have saved it.