Monday, March 21, 2011

Apple #513: Wolverines

Recently a friend and I watched a really good documentary about wolverines. Not the team, and not the X-Man. The actual animals. Turns out they are way cooler than I ever knew.

Nature: Wolverine: Chasing the Phantom
(Available for $11.93 through Amazon)

The documentary said that little is known about wolverines because so few people have seen them. Even some of the researchers who have spent decades studying wolverines have never actually seen them in person. They may have caught wolverines on camera, but they've never actually encountered a wolverine.

What the documentary did get across was that wolverines are super fast and strong for their size, they are indefatigable, and they have personality to spare. So I want to know more about these animals. What are some of the basic facts that we do know about them?

Wolverines have pointy faces but a snubbed nose, very thick fur that is a mixture of brown and black with golden hairs under the chin, a stout bushy tail, and huge feet with claws. This one is doing one of the wolverine's favorite things: running over the snow.
(Photo posted by Anonymous at care2)

  • Wolverines may look like a cross between a bear and a raccoon, but they're actually members of the weasel family.
  • They're not big -- only about 3 to 4 feet long and they weigh about 30 to 40 pounds. But they pack a punch in those little bodies.
Picture a Weasel—and most of us can do that, for we have met that little demon of destruction, that small atom of insensate courage, that symbol of slaughter, sleeplessness, and tireless, incredible activity—picture that scrap of demoniac fury, multiply that mite some fifty times, and you have the likeness of a Wolverine.
--Ernest Thompson Seton, 1953

  • Here's a 2-minute bit from a Wild Kingdom episode that gives a brief overview of the wolverine, and gives you a good idea of how they move. I wanted to embed it here but the dang link they provided didn't work.
  • Wolverines cover territories that are enormous relative to their size -- anywhere from 200 to 1,000 square miles.
  • In deep snow, when other animals typically slog away and sometimes founder, wolverines can cover as much as 15 miles in a day. And, by the way, they run the entire time. 
  • They're able to run like this over snow mainly because of their feet. Put simply, their feet are huge.

It's tough to tell how large the wolverine's paw is from this photo, but you can get a sense of how sharp their claws are. I'm more stunned by the fact that the wolverine is allowing himself to be held, though it looks like he won't put up with it for long.
(Photo from The Wolverine Blog)

This drawing of a wolverine's paw print isn't that great. For one thing, it's about half the size that it should be. But I posted this image because it gives a good idea of how the toes of the wolverine fan out. Because of the size of their paws and the way they spread out like this, it's as if the wolverines are running on snowshoes.
(Image from Through the Eyes of a Wolverine)

  • The Latin name for wolverine is Gulo gulo, which means glutton glutton.
  • They are so named not because they kill more food than they can eat or because they overeat, but because the animals they kill for food can be enormous compared to their size. They've been known to take down elk, moose, or caribou.
  • Most of the time, though, they kill smaller animals like rabbits or grouse or squirrels, or they eat carrion -- animals that are already dead. They're especially good at finding dead animals buried deep under the snow.
  • If they do kill or come across more food than they can eat at one time, they'll mark the food (spray it with their scent), bury it under the snow to preserve it, and come back for it later.
  • Eventually, they'll eat everything -- bones, teeth, skull, everything.
  • One person in the documentary said that one of the reasons he's so impressed with wolverines is because other animals that you normally think of as being really good in the mountains, like mountain goats, can still get taken out by avalanches. But wolverines not only survive the avalanches, they eat the animals that don't.
  • They are pretty much unstoppable.  When they're moving, which is most of the time, they're running. When they sleep, it's only for about three or four hours at a time. Then they get up and run some more.
  • Wolves, bears, and mountain lions are the wolverine's only predators. Those animals are also a wolverine's primary competitors for food.  But a wolverine is not so helpless against them.  A single wolverine is capable of driving a pack of wolves away from a kill.
  • They're not especially graceful and they don't see too well, so when they hunt, they use the element of surprise. They'll climb up a tree or onto a tall rock and when some likely animal wanders by, they'll jump on the animal's back. Sometimes this breaks the animal's back, or sometimes fighting ensues.

One common way that researchers have studied wolverines is to hang some sort of meat from a tree in front of a camera. Wolverines come around, climb the tree to get the food, and their motion triggers the camera shutter. That's how this picture was taken.
(Photo by Audrey Magoun, sourced from Chattermarks)

  • Wolverines are also excellent swimmers.
  • They live in dens under rocks or roots in the warm months. During winter, they dig dens deep into snow drifts. Often their dens include a complicated system of tunnels and chambers.
  • Wolverines generally keep to themselves except during mating. Both males and females may mate with more than one wolverine. When the female gives birth, she may have anywhere from 1 to 6 kits, any or all of which may have different fathers.
  • The babies are born in a den dug into the snow. They're born blind with white fur that camouflages them against the snow.  As they mature, their fur darkens.
  • Wolverines were hunted to near extinction because of their fur.  It's very thick and dense, so actually an entire coat made of wolverine fur would be extremely heavy. Now, if people use wolverine fur at all (some native people still do), they use it only to line the hoods of parkas because of its other remarkable quality -- it doesn't hold moisture and therefore it won't freeze.
  • The fact that wolverines used to be hunted a lot for their fur is one reason why few people have seen them -- there are very few of them left.  Their snowy and wild habitats are also going away, so they have retreated farther and farther north.

Wolverines live in the areas in black -- or at least, this is where they are believed to live as of 1999. The numbers refer to subspecies. (1) is Gulo gulo gulo (I'm not kidding) and (2) is Gulo gulo luscus.
(Map from San Francisco State University Department of Geography)

  • They once lived as far south as Arizona and New Mexico.  As you can see, they've moved quite a distance north. 
  • They also really don't like being around people. That's probably another reason why few people have seen them in the wild.
  • Wolverines aren't on US endangered or protected species lists because applications for them to be included were rejected for insufficient data. Nobody can find enough wolverines to conduct a census that anybody thinks is anywhere near accurate. [EDIT: soon this will be no longer true. As of February 2013, US wildlife officials are asking that wolverines be added to the endangered species list because their habitats are threatened by climate change. Only an estimated 250 to 300 remain.]
  • There is some good news, though.  In 2004, a wolverine was spotted in Michigan -- a state where no one has seen a wild wolverine in 200 years. They saw the animal near a town called Ubly, which is about 90 miles north of Detroit.

This is the wolverine that was seen in Michigan in 2004, photographed as it was running out of the woods and across a field. 
(Photo by wildlife biologist Arnie Karr via AP)

  • In 2010, a wolverine was spotted in Grand Teton National Park in Wyoming. Later, that same wolverine was seen in Colorado -- 500 miles south. The last time anybody saw a wolverine in Colorado was in 1919.
  • Researchers were able to catch him and put a radio collar on him.  They named him M56 (I think the M stands for male), and people are hoping to be able to monitor his movements.

See? Enormo-paws.
(Photo from Esquire)

  • If you think you've seen a wolverine, document as much of the experience as you can -- take pictures of the animal or its tracks, note your location by GPS or as specifically as possible -- and let the folks at The Wolverine Blog know about it.

If you're interested, here's the documentary I watched. It was on PBS, so your library probably has a copy of it.

Nature: Wolverine: Chasing the Phantom
(Available for $11.93 through Amazon)

National Geographic, Wolverine (Gulo gulo)
Arctic Animals, Wolverine (Gulo gulo)
Muirmaid, Wolverine
The Animal, Wolverine
Fur Commission USA, Fur types in brief
New Hampshire Public Television, NatureWorks, Wolverine - Gulo gulo
C. Breen, The Biogeography of Gulo gulo (wolverine), Biogeography, San Francisco State University
Colorado Division of Wildlife, Wolverine
Kurt Repanshek, Wolverine Sightings Growing in Rocky Mountain National Park, National Parks Traveler, August 6, 2010
David Runk, First Michigan wolverine spotted in 200 years, Associated Press, February 25, 2004


  1. "Chasing the phantom" available to view online:


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