Kristen Rozell skis past grizzly bear tracks pressed into a snowmachine trail near Fairbanks on April 23, 2023. (Courtesy Photo / Ned Rozell)

Kristen Rozell skis past grizzly bear tracks pressed into a snowmachine trail near Fairbanks on April 23, 2023. (Courtesy Photo / Ned Rozell)

Alaska Science Forum: Bear tracks on snow a sign of the season

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 Alaska.

As of this writing, however, middle Alaska 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 Alaska road last weekend, my wife and I saw bear tracks in the snow.

Those tracks belonged to a grizzly bear, according to Dick Shideler.

“That’s a big male,” Shideler said after seeing the photo. “It’s pretty amazing that it’s out wandering. Could be looking for a moose carcass.”

This map shows the location of bear tracks. (Courtesy Image / Ned Rozell)

This map shows the location of bear tracks. (Courtesy Image / Ned Rozell)

Shideler is a biologist retired from the Alaska 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 — including the frozen Arctic Ocean coast — made it seem like deep winter except for the brilliant sunshine.

“They probably couldn’t find much to eat besides carcasses (of animals that had fallen in winter) or the occasional live caribou or muskox,” he said. “They’ll eat whatever they can find, like dead grass. It’s definitely lean times when they come out, before ground squirrels or vegetation.”

Shideler noted that bears just out of hibernation are shifting from their lower metabolism of the past months to a more active state, “so their energy requirements aren’t as high immediately after emergence.”

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 airhole steaming above the snow might have been evidence a creature larger than a human was just beneath the surface.

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.

“Maybe the den warms up to the point where it gets uncomfortable for them,” Shideler said. “Or, with all that warm weather we had (in previous weeks) the bear could have picked a den location that might have flooded.”

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’s 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’s 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 Alaska 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.

More in News

The Norwegian Cruise Line’s Norwegian Encore docks in Juneau in October, 2022. (Clarise Larson / Juneau Empire File)
Ships in Port for the Week of May 28

Here’s what to expect this week.

(Michael Penn / Juneau Empire File)
Three people die on boat anchored off Sandy Beach

Drug use a possible factor in deaths of one man and two women during three-day span

The Mendenhall Glacier and surrounding area is seen under an overcast sky on May 12. A federal order published Friday bans mineral extraction activities such as mining in an expanded area of land surrounding the glacier for the next 20 years. (Ben Hohenstatt / Juneau Empire File)
Feds expand ban on mineral extraction near Mendenhall Glacier

20-year prohibition on mining, oil drilling applies to newly exposed land as ice continues retreat

(Michael Penn / Juneau Empire File)
Police calls for Thursday, June 1, 2023

This report contains information from law enforcement and public safety agencies.

Bulk food in Food Bank of Alaska’s Anchorage warehouse on April 21. (Photo by Claire Stremple/Alaska Beacon)
State roughly halves the number of Alaskans waiting on food aid, but more than 8,000 remain

By Claire Stremple, Alaska Beacon Mary Wood has been waiting for food… Continue reading

A white butterfly rests upon a fern Saturday at Prince of Wales Island. (Courtesy Photo / Marti Crutcher)
Wild Shots

Reader-submitted photos of Mother Nature in Southeast Alaska.

Photos by Lee House / Sitka Conservation Society
Aliyah Merculief focuses on her run while snowboarding at Snow Camp.
Resilient Peoples & Place: Bringing up a new generation of Indigenous snow shredders

“Yak’éi i yaada xwalgeiní” (“it is good to see your face”) reads… Continue reading

A polar bear feeds near a pile of whale bones north of Utqiaġvik. (Courtesy Photo /Ned Rozell)
Alaska Science Forum: Polar bears of the past survived warmth

In a recent paper, scientists wrote that a small population of polar… Continue reading

(Michael Penn / Juneau Empire File)
Police calls for Wednesday, May 31, 2023

This report contains information from law enforcement and public safety agencies.

Most Read