Wolverines' Need to Roam Spotlights Eco-Plan Vision

Brian Handwerk
for Ultimate Explorer

March 12, 2004

For more on the wilderness vision of the
Yellowstone to Yukon Conservation Initiative, watch href="http://www.nationalgeographic.com/ultimateexplorer/"
target="_new">Ultimate Explorer: One Wild Ride: Yukon to
Yellowstone Sunday, March 14, at 8 p.m. ET/PT on MSNBC
TV.

The inspiration behind the Canadian and United States national park systems can be found in the majestic mountain region that stretches from Yellowstone National Park, on the Wyoming-Montana border, to the Yukon Territory.

Today, that region has also inspired some new ideas about wilderness protection. Some conservationists argue that the Rocky Mountain region represents one of Earth's last, best opportunities to preserve a complete mountain ecosystem.

Groups like the Yellowstone to Yukon Conservation Initiative (Y2Y) say that realizing that vision, however, will require unconventional approaches outside the normal boundaries between nations, states, and protected areas.

Y2Y is championing the creation of an enormous ecoregion stretching nearly 2,000 miles (3,200 kilometers) from Wyoming to the far north of Canada's Yukon Territory, just 37 miles (60 kilometers) shy of the Arctic Circle.

The plan would link existing wilderness and natural areas with wildlife travel corridors to enable large predators and other animals to migrate. The concept presents an experiment in how mixed natural and human communities might coexist to the benefit of both.

The area eyed by conservationists for the proposed ecoregion includes towering peaks, rolling grasslands, salmon-filled rivers—and many human communities. Critics of the plan fear economic hardship if industries like logging are curbed.

But proponents argue that the plan's time is now.

"Recent scientific research reinforces what experience has already shown those of us who live in the Y2Y region—small islands of protection haven't been able to maintain the things we care about," said Jeff Gailus, Y2Y's communications coordinator.

"If we want to ensure that our children and grandchildren can enjoy clean water and abundant wildlife, we need to think on a larger scale."

One animal that helps spotlight the potential benefits to wildlife of the core Y2Y vision, albeit on a somewhat smaller scale, is the wolverine.

The reclusive predator (Gulo gulo) is the largest member of the weasel family. A typical adult female weighs 17.5 to 22 pounds (8 to 10 kilograms), while males tip the scales at 26.5 to 31 pounds (12 to 14 kilograms).

Gailus calls them a "great focal species" for Y2Y.

Wandering Wolverines

Little is known about wolverine populations in the Rocky Mountain region. The animals are rarely spotted and live in very remote areas.

"Wilderness areas are probably more important for wolverines than most species, simply because the areas we choose for wilderness tend to define what we understand as wolverine habitiat," said Jeff Copeland, a wildlife biologist at the U.S. Forest Service's Rocky Mountain Research Station in Missoula, Montana.

More prevalent in Alaska and the Canadian north, wolverines are found in isolated pockets of suitable habitat along the Rocky Mountain chain.

"They've adapted to a lifestyle at population densities some people would think too low to for persistence," Copeland said. "In 500 square miles (1,295 square kilometers) you could expect to find six to ten wolverines. Few other species can persist at those densities."

Bob and Kris Inman—huband and wife biologists with the Wildlife Conservation Society who are based in Bozeman, Montana151;study wolverines in the greater Yellowstone area.

The paucity of wolverines makes their work a challenge. They spend four months each winter trapping wolverines. In three years, they've caught only 17 individuals. (The researchers have managed to recapture nearly all of the animals during that time, however.)

Wolverines are powerful enough to chew through the six- to eight-inch-thick (15- to 20-centimeter-thick) log walls of the traps the biologist use to capture the animal. The predators often escape their traps before the researchers can arrive to examine them, making their work frustrating at times.

While wolverine densities are low, the animals get around.

"One of the things that's really phenomenal is that the home range sizes are huge for adult animals," Kris Inman said.

In Idaho, male wolverines have been known to roam over 580 square miles (1,500 square kilometers) of home range. The animals pay no heed to fence lines, road cuts, and other human boundaries.

Bob Inman told Ultimate Explorer of one roving young male that the couple captured and collared with GPS-tracking equipment.

The wolverine "used almost half of the Yellowstone ecosystem," Inman said. "We've located him in … nine different mountain ranges, two national parks, three states, and three different national forests"

The predator "shows that these animals use multiple jurisdictions, and a single animal is not a resident within a single boundary," Kris Inman said.

Copeland, the U.S. Forest Service researcher, and other scientists are studying how wolverines cover these immense distances and connect seemingly isolated populations as they roam. The information could reveal what wildlife corridors might be crucial to the protection of wolverines and other animals.

"We want to learn how they move on the landscape and how they respond to human and natural features in the environment," Copeland said. "Do they tend to avoid roads or snow machine trails? Do they select specific habitat types to move through, along ridges or through drainage bottoms?"

Human Footprints

Information on how wolverines deal with the human world is particularly crucial. Even a region relatively free from the intensive development seen elsewhere in North America is feeling more of a human presence these days.

"Based on where wolverines live, in the past, winter was a kind of de facto refuge for them, because not a lot of people could get access to these isolated regions," Copeland said. "But now we can."

"Snowmobile technology has increased so that you can pretty much go anywhere," Inman said. "Also, more people are accessing the backcountry with heli-skiing [and] backcountry skiing. If [wolverines] are susceptible to human disturbances, we don't know what that impact means. It is a major goal of our research to determine if and how recreation impacts wolverine populations."

Such information could prove useful to land managers throughout the Y2Y region.

"Wolverines seem not particularly interested in our presence," Copeland said. "It's that characteristic of the animal that to me really represents the wilderness image."

"It's a very easy species to ignore, but we know it's there. And if we're really as intelligent a species as we think we are, then we have to recognize that our actions affect these animals," he said. "It's our responsibility to know what those impacts are and to deal with them."