Photograph by Paul Nicklen, National Geographic Published
February 8, 2011 Built for the cold, wolverines make their homes
mostly in the northern forests and tundras of North America,
Europe, and Asia. The carnivores are rarely found in places
where temperatures get higher than 72 degrees F (22 degrees C).
During winter, the animals' thick, oily fur serves as
insulation, while large, padded paws help them run across deep
snow. In the spring, wolverines build dens in the lingering
snowpack to shelter newborns. Currently about 15,000 or more
wolverines are believed to roam Canada, and an unknown number
reside in Alaska. Only a few dozen to a few hundred are believed
to live in the contiguous United States, almost all of them in
the mountains of Wyoming, Idaho, Montana, and Washington State.
The new study shows that climate change might endanger
wolverines in the mainland U.S. by eliminating springtime snow
and significantly increasing summer temperatures. (Related
pictures: "Ten U.S. Species Feeling Global Warm