THE SITE WAS UNFENCED back then, and grizzlies
often came to rummage for leftovers. Manville
was watching a bear feast on a hefty scrap of
meat when he noticed movement toward the
edge of his car’s beaming headlights. It was a
wolverine, staring intently at the bear and the
meat. What else could it do? It weighed maybe
30 pounds; the grizzly weighed several hundred.
“Then all at once the wolverine ran up and bit
the bear right on the butt,” Manville says. “The
grizzly whirled and swiped with a paw, but the
wolverine was already racing around to one side.
It grabbed the meat and ran off into the dark.”
A wolverine doesn’t seem like a reasonable
beast, for it acts too tough and brazen for its size.
But at barely three feet long from keen nose to
bushy tail, an average wolverine will claim a
territory of 100 to more than 500 square miles,
then patrol it at an unrelenting pace, sniffing,
probing, hunting, scavenging, and defending
its home from rivals.
In the five years that I volunteered with a
groundbreaking study in Montana’s Glacier
National Park, I tracked one radio-tagged male
as he climbed 1,500 feet straight up an ice-
packed chute on a sheer mountainside and
crossed the Continental Divide. The ascent took
him less than 20 minutes.
Another male scaled the park’s highest sum-
mit—10,466-foot-high Mount Cleveland—in Jan-
uary, when the peak was a towering ice sculpture.
He covered the last 4,900 feet in 90 minutes.
Within the next 10 days he climbed other crests
to the west, turned north into British Columbia,
One night years ago,
biologist Albert Manville
drove to a garbage dump near
Lake Louise in Alberta’s
Banff National Park.
loped east across the divide and on through
Waterton Lakes National Park in Alberta, and
returned south across more massifs to get back to
Glacier. No big deal. Within a day or two he took
off and made the journey all over again.SKUNK BEAR. MOUNTAIN DEVIL. Demon of the
North. For centuries wolverines were defined not
only as greedy, god-awful smelling, and eerily wily
and elusive but also as foul-tempered, wantonly
destructive, and a danger to people in the back-
country. But none of these characterizations fit.
Gulo gulo (from the Latin word for “glutton”) is
native to Arctic, subarctic, and mountain regions
of the Northern Hemisphere. The species is part
of the large and varied mustelid family, many of
which have revved-up metabolisms. The group
includes martens, weasels, badgers, honey
badgers, otters, and sea otters. Of the group’s
nonaquatic members, the wolverine has the heavi-
est skull, thickest jaws, biggest teeth, largest body,
and largest feet. A single gulo can bring down
prey as large as an adult caribou, and unverified
reports describe wolverines occasionally forcing
wolves and even big bears away from a carcass.
The last thing a wolverine is, so it would
seem, is vulnerable. But trappers, hunters, and
livestock owners erased the animal from much
of Eurasia. In the New World, government-
sponsored predator eradication campaigns took
a heavy toll. By the 1930s the species had disap-
peared from the lower 48 states.
Yet wolverines are tenacious survivors that
still have strongholds in Alaska and parts of116 NATIONAL GEOGRAPHIC