The climate crisis is driving bears to town as their food and habitats come under increasing threat

Wildfires, droughts and increasing temperatures are affecting bear behaviour and their ability to forage

Sheila Flynn
in Denver, Colorado
Wednesday 18 August 2021 12:25 BST
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Bears are coming into town as the climate crisis threatens their habitats and food

The images seem to come on a near-daily basis: Bears wandering through suburban streets caught on security cameras. Polar bears nearly outnumbering coastal Alaskans. Cubs sauntering down the aisles of a California supermarket.

As humans make increasingly concerted efforts to battle the deepening climate crisis, our furry friends are facing their own challenges.

Ongoing studies about how climate change is influencing bear behaviour across the globe are underway but have yet to yield concrete results, aside from in Alaska. But if it seems like bears are coming into town more often, it’s because they probably are.

Experts on the ground – and even residents of bear-heavy areas – verify that there’s a definite cause-and-effect when it comes to climate and human/bear interaction. It’s mostly down to food availability in something of a common-sense reality.

Nowhere is this more evident than in the Arctic, where sea ice is melting earlier each year, and more dramatically, leaving polar bears without their major food source of ice seals.

“Polar bears are spending more time on land, and the reason that they’re doing that is that there’s less sea ice habitat available to them,” Todd Brinkman, a wildlife biologist and associate professor at the University of Alaska, told The Independent.

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“Usually in September in Alaska is when we see our sea ice minimum ... they’re not feeding on the ice seals, because they’re going to be way off shore with the sea ice and inaccessible – so they have to switch to new land-based food sources, which haven’t been part of their diet over the last several thousands of years.”

With more bears on land more of the time comes higher risks of human interactions, which not good for either bears nor people.

But in a place like Alaska, where the climate crisis impacts are severe, both bear and human communities are forced into co-existence along the coast.

The Arctic has warmed “three times faster than the world as a whole, leading to rapid and widespread changes in sea ice, land ice (glaciers and ice sheets), permafrost, snow cover and other physical features and characteristics of the Arctic environment,” according to a summary of the Arctic Council’s 2021 Arctic Climate Change Update.

“The other thing that happens in the fall is there’s a whole bunch of communities on the north coast of Alaska that harvest bowhead whale,” Dr Brinkman tells The Independent.

“So that’s another major attraction to the bears. After they harvest the whale, they tow it to shore, they butcher it and then the carcass remains – and that’s a food source for the bears.”

While polar bears are plagued by declining sea ice and lack of seals to eat, climate-driven conditions across the rest of North America are impacting food sources for other bear populations – and forcing them to venture further afield and into neighborhoods.

“Things like drought, that affects bear foods,” John Hechtel, president of the International Association for Bear Research and Management, tells The Independent.

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“It can affect berry production. It can affect returns of salmon to certain streams ... if the water temperatures get too hot or if there’s not enough water in the stream system to allow adequate salmon. There’s a lot of sort of interconnected relationships between climate, the habitat and potential food sources.”

He adds: “It can be fairly indirect, like warmer temperatures that, in the winter time, allow beetle larvae to expand their range and to attack trees that produce food sources for bears. It can be fires that take out habitats.”

Climate and environmental impacts have knock-on effects for years, experts say. Bears can hibernate in dens for up to seven months of the year, and when they emerge, their primary focus is to build up fat reserves for the following winter. Only by maintaining nutrition can they reproduce, survive and thrive.

“Whenever there’s drought and it dries up the berries, you’ve got high mortality among cubs,” Minnesota biologist Dr Lynn Rogers, known as the “Jane Goodall of bears”, told The Independent.

“And females are unable to maintain their pregnancies, so the effects can last for years after prolonged drought.”

Disasters such as drought and fires have happened throughout history but are increasingly intense, more frequent and unpredictable due to the climate crisis - and will remain so for around the next 30 years, according to the latest UN climate report.

Beyond mid-century, these extreme events could become even more dire if humanity doesn’t rapidly reduce planet-heating greenhouse gas emissions.

In northern Minnesota, Dr Rogers studies black bears through the North American Bear Center, which he founded in 1995 - though the 82-year-old has been studying bears for more than half a century.

He has observed firsthand an increase in bears coming to town.

“Last year, we had a big drought that dried up the berries, and we got the same thing this year,” he tells The Independent. “And I have never seen so many bears coming into local towns and going house to house for tidbits of garbage and birdseed.”

He adds: “It used to be believed that, when bears come out of the forest into town, it was simply that they were lazy bears that had become habituated ... and food conditioned. But then from everything I saw, it was mainly just hunger.”

(@tishacampbellmartin / Instagram)

However there may be a flip-side in certain northern communities, he says. Warmer temperatures could possibly expand food sources for bears when deciduous trees and their culinary offerings thrive for longer.

That obviously doesn’t apply to locations such as Alaska, and the warmer temperatures may actually be throwing off behaviour that then leads to more problems finding food, Dr Brinkman tells The Independent.

“We’re starting to see more research roll out on brown and black bears,” he says. “So these kinds of studies that are being developed are focused on how you have warmer shoulder seasons, warmer falls, earlier springs. That might mean bears are going into hibernation earlier and coming out sooner.

“I don’t know how strong the data is on this, but people are hypothesising that ... say you have a really unseasonably warm spring, and the bears’ environmental cues suggest it’s time to come out of the den. The snow’s melting, let’s go out and forage.

“Well, they come out, but it’s too early in the spring. A lot of those plants they would be consuming at that time aren’t ready. That could put them in a vulnerable situation. Any time a bear doesn’t have enough food, it might behave differently than it would during a normal food year.”

It is hoped that further research will lead to more suggestions of how to fix bear food shortages – or at least minimise human interactions when they inevitably occur.

Dr Rogers described a California drought near Lake Tahoe in 2007 when a few intrepid researchers took matters into their own hands.

“That year, experts told the people, just remove your attractions [like garbage] and the bears will go back in the woods – not realising there was nothing in the woods,” he tells The Independent. “Drought had ruined the berry crops and everything.

“There was a group there that tried something new to learn something new. They did air drops of food and they backpacked food up into the hills. Where they did that, the problems ended. It was illegal, what they were doing – and so where they didn’t dare do it because they’d get caught, problems continued.”

It’s illegal in the US to feed wildlife such as bears and moose. But the Tahoe group’s idea worked, and solutions will have to be found to similar problems, whether it be in Alaska, California or elsewhere.

To some extent, bears foraging for food among humans has always been a feature of modern life in rural communities. It has been fuelled in recent decades by the encroachment of residential communities in formerly wild landscapes that are traditional bear habitats.

The proliferation of social media and CCTV - with bears even inadvertently ringing doorbells - has perhaps made bears popping up on people’s front porches seem more common given the viral value of such clips.

But it’s undeniable that the climate crisis is influencing wildlife, and bears are far from immune.

In the meantime, experts urge the usual precautions when it comes to dealing with bears who’ve ventured further from their forest homes. Most of it comes down to people simply avoiding “being really careless with food and garbage,” Mr Hechtel tells The Independent.

“Bears take the path of least resistance a lot of the times,” he says. “And all of a sudden, here’s an abundant source of food in people’s garbage cans that they can access, especially if there’s a shortage of some natural food items. Then that can draw them in, which can lead to conflict.

“Biologists are often trying to find ways to help people and bears get along in ways that are not detrimental to either. And sometimes, you can do fairly simply things like electric fences – solar-powered electric fences – around beehives or chicken coops. Stuff like that.

“The larger habitat [changes] or changes in major food sources ... can be a little more difficult.”

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