“I was at 10,000 feet or so,” says wildlife researcher Phil Manlick. “My friends were fishing on one side of an alpine lake, but I was sleeping, and facing the other direction. I opened my eyes and saw a wolverine running across a snowfield on the north side of the canyon. First, I gestured wildly, trying to get the group’s attention. Then I yelled. They still didn’t hear. One of the group had been talking all week about how much he wanted to see a wolverine, so finally I shouted his name, ‘ALEX!’ at the top of my lungs. Either the wolverine was named Alex,” Phil jokes, “or I disturbed him a bit, because the large weasel stopped and looked at us. Then the wolverine turned and ran straight up over one of the highest passes in the Tetons, right into Idaho.”
Phil has researched various animals all over the country, from elk and mule deer in Oregon, to cougars and grizzly bears in Washington. He has tracked wolves in the Grand Tetons, and now pine martens in Clam Lake, WI. But from the excitement he shows in his face, voice, and even gestures as he tells this well-worn story, you can tell that this was a highlight of his animal encounters.
And it’s no wonder. Wolverines are among the most elusive creatures on the planet, and have become an almost mythical beast. As the largest land-dwelling member of the weasel family, wolverines take weasels’ reputations for fierceness to the highest level. By some estimates, if a wolverine were the size of a bear, it would be the strongest creature on Earth. It is no exaggeration that the wolverine is the strongest animal of its size.
With this strength of body and of will, wolverines live in some of the toughest terrain – the most rugged, remote and fiercely raw – and can prey on large animals like deer, moose, wild sheep, and elk. Wolverines are opportunistic feeders that also eat carrion, smaller mammals, eggs, roots, and berries. Food in their harsh habitats can be scarce, so they have adapted to a feast-or-famine lifestyle by reportedly eating up to 40 pounds (their own bodyweight) at one time when food is available. This earned them the scientific name Gulo gulo, which means “glutton” in Latin.
Even rock-hard frozen food doesn’t present a problem to wolverines, since they, like other mustelids, possess a special upper molar in the back of the mouth that is rotated 90 degrees, towards the inside of the mouth. This special characteristic allows wolverines to tear off meat from prey or carrion that has been frozen solid.
This and other adaptions give wolverines an advantage in winter. Big, padded paws help them run through deep snow, and a relatively large, compact body and a thick winter pelage minimizes heat loss. Their dark, oily fur is also highly hydrophobic, making it resistant to frost. Humans in many cultures have taken advantage of this trait by using the fur to line jackets and parkas. Scientists estimate that wolverines do not experience cold stress at even negative forty degrees Fahrenheit.
Wolverines seem tough enough to withstand almost anything. And yet, their population in the United States declined precipitously by the turn of the last century, and is still declining today. Poisoned carcasses and fur trapping precipitated the initial decline. A completely different set of stressors acts today.
Spring snow cover through mid-May is essential to wolverine reproduction, since females raise their kits in snow dens that provide protection from the cold and predators. In fact, spring snow cover is the one factor that all wolverine habitats across the continent have in common. Although Wisconsin has not had regular spring snow cover recently, scientists surmise that the Little Ice Age from 1350 to 1850 may have provided better habitat for wolverines here before accurate records were kept.
The distribution of current wolverine records in the contiguous United States is limited to north-central Washington, northern and central Idaho, western Montana, and northwestern Wyoming, although rare sightings do still occur in the Great Lakes region. The wolverine was on Michigan's endangered species list until the late 1990s, when it was removed from the list because it wasn't expected to return.
Although the wolverine is a candidate for the Federal Endangered Species List, its main threat is a warming climate, which cannot be addressed under the current Endangered Species Act. A National Center for Atmospheric Research study found that “Unless the wolverine is able to very rapidly adapt to summertime temperatures far above anything it currently experiences, and to a spring with little or no snow cover, it is unlikely that it will continue to survive in the contiguous U.S. under a high or medium-low carbon emissions scenario.”
The good news is that if we can reduce our emissions to the lowest emissions scenario, we can make help these mythical beasts survive in the Tetons, not just in legends. Phil would appreciate that, and so would his friend Alex.
For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The current exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013.
Find us on the web at www.cablemuseum.org to learn more about our exhibits and programs. Discover us on Facebook, or at our blogspot, http://cablemuseumnaturalconnections.blogspot.com/.