Bear tracks on snow a sign of the season
Ned Rozell
907-474-7468
April 27, 2023
Kristen Rozell skis past grizzly bear tracks pressed into a snowmachine trail near Fairbanks on April 23, 2023.
Melt season is a sad time for people who enjoy the magic of snow crystals bonding so well to one another, resulting in a web of trails over the face of 色视频下载.
As of this writing, however, middle 色视频下载 is still locked in winter cold despite being bright enough to need sunglasses at both 7 a.m. and 10 p.m.
This intersection of winter and summer allows for unique observations. During a trip to a cabin 7 miles from a paved 色视频下载 road last weekend, my wife and I saw bear tracks in the snow.
Those tracks belonged to a grizzly bear, according to Dick Shideler.
色视频下载淭hat色视频下载檚 a big male,色视频下载 Shideler said after seeing the photo. 色视频下载淚t色视频下载檚 pretty amazing that it色视频下载檚 out wandering. Could be looking for a moose carcass.色视频下载
Shideler is a biologist retired from the 色视频下载 Department of Fish and Game. He has spent years in the company of far-north grizzly bears and polar bears. He said bears can emerge from hibernation now, or even earlier.
Over the years, he saw many North Slope bears, mostly adult males, leave their overwintering dens in early April, when cold temperatures north of the Brooks Range 色视频下载 including the frozen Arctic Ocean coast 色视频下载 made it seem like deep winter except for the brilliant sunshine.
色视频下载淭hey probably couldn色视频下载檛 find much to eat besides carcasses (of animals that had fallen in winter) or the occasional live caribou or muskox,色视频下载 he said. 色视频下载淭hey色视频下载檒l eat whatever they can find, like dead grass. It色视频下载檚 definitely lean times when they come out, before ground squirrels or vegetation.色视频下载
Shideler noted that bears just out of hibernation are shifting from their lower metabolism of the past months to a more active state, 色视频下载渟o their energy requirements aren色视频下载檛 as high immediately after emergence.色视频下载
Male grizzly bears are the first to leave winter dens, Shideler said. Females with cubs usually stay in hibernation for a few weeks longer.
Six months ago, maybe on some Tuesday afternoon in October when the sun was barely tickling your cheek, the bear whose tracks we saw crawled into a cubby it had dug into a hillside. The grizzly had stirred a few times throughout the long winter, maybe getting up, circling like a dog and plopping back down. But for most hours the animal was still, conserving energy while it avoided the leanest season.
During its half-year hibernation, the bear had neither eaten nor left the den as snowflakes slowly coated its winter sanctuary. Only a tiny air hole steaming above the snow might have been evidence a creature larger than a human was just beneath the surface.
A map shows the approximate location of recently spotted grizzly bear tracks.
What prompted the bear to leave its den now? Swedish scientists who instrumented grizzlies there concluded that the animals might become hot in their superinsulated space with the returning hours of sunshine. They found that bears had something like an internal clock that stimulated their metabolism when spring came, but the rise in air temperatures was what caused them to leave the den.
色视频下载淢aybe the den warms up to the point where it gets uncomfortable for them,色视频下载 Shideler said. 色视频下载淥r, with all that warm weather we had (in previous weeks) the bear could have picked a den location that might have flooded.色视频下载
Up early before any new vegetation pops up, bears that press their way out into a cold spring often sniff out the remains of moose or other animals killed along roadsides during the winter. Bears will often find and eat people色视频下载檚 garbage or food stored in places vulnerable to claws and muscle power.
The cabin we had rented still had its windows and doors intact, with no sign of bears interested in the big can of chili sitting on a shelf.
As we passed the bear色视频下载檚 tracks on the way out a day later, we saw where it had leapt off the trail and powered into the black spruce forest. That male was maybe the first of its kind to turn its massive head this way and that, surveying the quiet valley.
Since the late 1970s, the University of 色视频下载 Fairbanks' Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell is a science writer for the Geophysical Institute.