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Defenders Magazine
Sympathy for the Devil Bear
Wolverines aren't evil, just feisty - and overlooked.
brucecoleman.com (captive)
The single-engine airplane bounces in the wind as pilot Doug Chapman of the Greater Yellowstone Wolverine Program flies low over a rocky 9,000-foot peak in southwestern Montana. An antenna mounted beneath the wing has just picked up a signal from a wolverine implanted with a radio transmitter, and Chapman banks the plane to get a bead on its location. A scanner in the cockpit identifies the wolverine as F121, a female captured by researchers last winter.
"I think she's down there in that conifer stand," says Chapman, who makes weekly flights to track wolverines during the summer. Chapman circles three times and records F121's coordinates so ground trackers can attempt to pick up the search the next day. Airplanes are key to researching elusive wolverines, stocky carnivores that look like a cross between a skunk and a bear. Despite their squat bodies and short legs, wolverines are quick on their feet—covering 20 or more miles of hilly terrain per day in search of carrion and small prey. "They can cross a mountain range," says U.S. Forest Service wolverine expert Jeff Copeland, "like you or I cross the street."
Their wandering habits and preference for remote habitat makes wolverines the "least-understood, least-studied carnivore in the lower 48," says biologist Bob Inman, leader of the nonprofit Yellowstone wolverine program, based in Ennis, Montana. They are also among the rarest of the country's wild creatures; researchers suspect fewer than 1,000 are left in the lower 48 states. As a result, Defenders of Wildlife and other conservation groups have fought for years to get wolverines protected under the Endangered Species Act. But the U.S. Fish and Wildlife Service, citing a lack of information, has twice rejected petitions to list the creatures.
Hoping to improve our understanding of wolverines, researchers are now putting the animals in the spotlight. Inman, a former bear researcher, is halfway through a 10-year study of wolverines in the Yellowstone region. With a $350,000 annual budget funded by donations from individuals and conservation groups, the biologist and his team are beginning to answer basic questions about wolverine reproduction, habitat needs, food sources and how increased human activity in the mountains affects their populations. In addition, Copeland is studying wolverines in Glacier and Yellowstone national parks, and the mountains of southwestern Montana. Meantime, the first-ever international wolverine conference was held last summer in Sweden, where researchers began drafting a worldwide conservation plan for the animals. "They are finally getting the attention they deserve," says Judy Long of the Wolverine Foundation, an education group based in Kuna, Idaho.
The largest terrestrial member of the weasel family, wolverines live up to 12 years and have a keen sense of smell that helps them locate food, primarily carcasses of deer and elk, from miles away. Opportunistic feeders, they are believed to also prey on marmots, pikas and other alpine dwellers. Their scientific name, Gulo gulo—the glutton—speaks to their appetites. Wolverines sometimes trashed pioneer cabins in search of food. Renowned for their ferocity (there are documented instances of wolverines taking down moose), 30-pound wolverines stand their ground when it comes to a meal. Two of the wolverines in Inman's study died fighting black bears, which are 10 times bigger, for elk carcasses. "That shows you how tough they are," Inman says. Humans remain the biggest threat, however. Of the nine wolverines in Inman's study group that had died by last fall, five perished at the hands of people—a car struck one and Montana trappers took four.
Defending Wolverines
With its low numbers, reduced range and many threats facing it, the wolverine would seem an obvious candidate for protection under the Endangered Species Act.
In 2000, Defenders of Wildlife submitted a petition to the federal government to list the wolverine under the act. In 2002, after the Bush administration failed to act on the petition, Defenders filed suit. In late 2003, the administration finally issued its ruling on the petition, stating that there was insufficient scientific evidence to list the wolverine. Convinced that the wolverine should be protected, Defenders filed suit last year to overturn the government's decision. The case is now pending.
In addition to its efforts in court to protect wolverines, Defenders has worked to ensure that the animals are considered in federal land management decisions. The group was also successful in pushing the state of Montana to restrict trapping of wolverines. In addition, through its Earth Friends Wild Species Fund, Defenders is supporting volunteers who are tracking and monitoring this elusive animal in Mt. Hood National Forest in Oregon.
"Wolverines are some of the most overlooked of our forest carnivores," says Nina Fascione, vice president for field conservation at Defenders, "and they are in urgent need of our attention and protection."
Packila, a wiry blond assistant whom McCue calls "Speedy" because he continually disappears over hilltops, rotates a hand-held antenna and picks up a blip. We head in that direction, then lose the signal. "That's the challenge with wolverines," says McCue, pausing between words to catch his breath in the thin mountain air. "One minute you think you're closing in, the next they're over the ridge and gone." It continues this way for the next three hours as we hike non-stop at a breakneck pace, crossing deep drainages and scrambling across steep fields of loose boulders. The radio receiver occasionally picks up a faint blip, then turns to static. It almost seems the wolverine is taunting us by remaining just out of eyeshot. McCue, an outdoorsman who cut his teeth in carnivore tracking while studying lynx in Maine, is unfazed by our failure. Even with radio-tracking devices, McCue estimates he succeeds in spotting a wolverine only 15 percent of the time. Without such gizmos, he says, someone could spend his entire life in these mountains and never see a wolverine.
The wolverines that have repopulated the northern Rockies are believed to have taken advantage of a window of opportunity during the mid-1900s, after the end of large-scale trapping and before human populations in the region began booming. How sad it would be, conservationists say, if wolverines are again forced out—this time because of uncontrolled recreation.
"Wolverines are an amazing animal that captures the American spirit," says David Gaillard of the Predator Conservation Alliance in Bozeman, Montana. "They are tough and tenacious survivors that scratch out a living in some of the most brutal areas of the country. We need to take steps to ensure they remain a part of the western landscape."
Contrary to common perception, wolverines are unrelated to wolves. Nobody knows for sure how their name originated and stuck, but they have been called everything from skunk bears to devil bears through the years. Wolverines are found in cold forests and tundra in Europe, Asia and North America. In the United States, the creatures once occupied many of the northernmost states, and lived in high-elevation habitat as far south as New Mexico and California. But they were eliminated from the lower 48 around 1900 by trappers and government-sponsored carnivore eradication efforts. Today they are found in less than a third of their historical range, and their only known breeding populations in the contiguous states are in the northern Rocky Mountains of Montana, Wyoming and Idaho, and a portion of Washington's Cascade Range.
These cold, desolate mountain landscapes contain little food and thus support low numbers of the animals. To find enough to eat, wolverines must patrol massive home ranges. Males cover territories as large as 500 square miles, females 250. "Wolverines eke out a living where no other carnivores want to go," Inman says. "They are at the boundary of what's physically possible."
Studying such a mobile species tests the physical limits of researchers. One female in the study regularly climbs a 40-degree slope over an 11,000-foot peak in the dead of winter to reach territory on the other side. So Inman employs not only a pilot, but more than a dozen trackers and trap builders, along with a veterinarian. Much of the fieldwork takes place during winter, when trackers trudge through deep snow on skis to find the critters, dragging their equipment through the mountains. The team members build large log traps by hand at timberline and bait them with road-killed deer. When a hungry wolverine takes the bait and the trap's door closes, a radio signal is emitted. Team members then ski in and anesthetize the wolverine, and the veterinarian carefully implants a transmitter in the animal's abdomen.
"In a good winter we will capture seven to eight wolverines," Inman says from his basement office, which is cluttered with wolverine reports and studies. "That's with a dozen people working full-time." He shakes his head and laughs at the difficulty. Through the first four years of his study, Inman's team caught 26 wolverines. "You can see why wolverines have not been well studied. It takes many years and a large output of man-hours to get a good sample size."
But the study is already yielding fascinating results, thanks to Inman's use of global positioning satellite—or GPS—collars. Airplane surveys allow researchers to locate animals, but they give no detail about an animal's movements between flights. GPS collars, by contrast, provide a detailed map of a wolverine's every movement across the landscape.One GPS-collared male, M304, became the buzz of the wolverine research community when he cruised more than 250 miles during 19 days in 2002—from Wyoming's Teton Range to Idaho's Portneuf Range, then back again. During the month and a half he wore the collar, the young male crossed eight mountain ranges in Wyoming, Montana and Idaho. Such large-scale movements had never before been recorded in wolverines. Young males such as M304, which are searching for new territory and mates, are the most prolific travelers, but all wolverines cover large distances because food is scarce in the rugged, rocky landscapes of the West.
M304 died shortly thereafter when he was taken by a trapper in Montana, which (along with Alaska) has a legal trapping season. Conservation groups have fought unsuccessfully to end Montana's trapping season. In a partial victory, the state this year lowered the take to 12 wolverines annually.
Females begin reproducing at age three and have two offspring roughly every other year, a low reproduction rate that makes them susceptible to population declines. Females give birth in mid-February in dens built beneath the snow amidst logs and boulders at timberline. Little else is known about den sites because they are so difficult to find. Copeland says fewer than 10 dens have ever been located in the lower 48. "We think the primary reason they locate dens so high in the mountains is for security," he says.
But increased winter recreation is decreasing this security. Snowmobile use has grown exponentially in the northern Rockies over the past 20 years. So-called "high-marking," when snowmobilers gun their machines straight up the steep slopes of alpine basins, is a popular and virtually unregulated sport. Backcountry skiing, snowshoeing, helicopter-skiing and ski-area expansions likewise threaten wolverine habitat. "If females are expending energy to avoid humans in the winter," Inman says, "that would definitely affect their reproductive success."
The mountains wolverines inhabit are like isolated islands. "As more roads and subdivisions are built, we're concerned about whether wolverines will be able to continue moving between these islands," Inman says. "To me, this is all evidence of their vulnerability."
The day after my flight with Chapman, I set out on foot with trackers Tony McCue and Mark Packila in search of F121 atop the mountain ridge. The two trackers want to see if F121 is traveling with youngsters (it is unknown whether she gave birth). They also hope to collect prey remains or scat that would indicate what the wolverine has been eating. Any information about the elusive creatures is treasured.
