Anxiety on the tundra
CLIMATE CHANGE IS A CLEAR AND PRESENT DANGER TO THE ALREADY-SHRINKING POLAR BEAR POPULATION THAT DRIVES TOURISM AND MUCH OF THE RELATED ECONOMIC ACTIVITY IN CHURCHILL.
A pair of cubs, roughly 1.5 years old, nurse amongst the rocks near the shores of Hudson Bay. (Sarah Lawrynuik/Winnipeg Free Press)
OCT. 31, 2020 — WINNIPEG FREE PRESS
CHURCHILL — The rocks fly out from beneath the tires of Angela Mak’s Ford F-150 as she cruises down the gravel road along the coast of Hudson Bay just east of Churchill.
It’s a routine. Every day from July until November she comes out here looking for polar bears.
Mak and her husband Bill Fong are originally from Hong Kong, but moved to Vancouver in the early ‘90s. In 2017 they travelled to Churchill during bear season — October and November, when the bears move out onto the sea ice.
After that one trip, their hearts were set on Churchill. First they bought a house in town to host friends and other guests, then they bought a small hotel when it went on the market in 2019.
The goal was to be as close to polar bears as often as possible.
As Mak cruises down the road, her excitement is palpable. She adores the enormous creatures. She slows down and makes a U-turn on the gravel road to bring the vehicle to the shoreline side of the road. She points.
Angela Mak shows off her polar bear photos that she’s bound in a book. (Sarah Lawrynuik/Winnipeg Free Press)
"You see them there?" she asks.
Camouflaging among the rocks is a mother bear and her two cubs. Based on the size, the cubs are about a year-and-a-half old, but polar bears stay with their moms for two to three years, nursing for the majority of that time.
One of the cubs starts nudging its mother after waking from a slumber. Someone’s hungry. Appearing somewhat annoyed at first, the mother bear gets up and walks over to a different set of rocks. She uses a tall, flat rock as a backrest and she sits up like she’s in a chair, exposing her chest for both cubs to feed in tandem.
Mak is giddy with excitement. As she snaps images of the mother nursing through her enormous telephoto lens; tears well up in her eyes. She keeps looking back into the truck to make sure her other passengers are also paying attention to this magical experience.
She truly loves these animals. The novelty never wears off for her.
The animals are accepting of the human gazes upon them, going about their business as usual. One cub catches a smell and looks towards the vehicle, a big milk moustache across its furry snout.
Once lunchtime is over, mother and cubs lumber down the coast and hop into the water. They swim east, with just their heads bobbing up and down in the waves, three in a row. They shake out their fur before walking through a commercial gravel pit and out of sight of prying eyes.
The summer months are known as a polar bear’s fasting period, for everyone but the insatiable cubs who bring their meals to go. The animals gorge themselves during the winter as they prowl across the sea ice in search of seals. Then, as the ice breaks up in the summer, they come ashore for months of roaming the land and living off their fat stores. They burn off approximately one kilogram of body weight every day they go without food.
The looming problem for the animals is that in Hudson Bay (and across the Arctic) the number of days of sea ice cover is declining significantly.
On average, the bay is losing approximately one day of sea ice cover every year. Because of the changing climate, about a month of ice cover has been lost over the past few decades, says David Barber, Canada’s research chair in Arctic system science.
Andrew Derocher, a professor of biological sciences at the University of Alberta, has been studying polar bears for nearly 40 years. SUPPLIED PHOTO
But of course, the change is not uniform. There are still good years, where sea ice cover stays longer, and bad years, which are particularly hard on polar bears.
"If you look across the Arctic this year, sea ice is at very low abundance overall. But if you look at the western Hudson Bay population, it’s actually done quite well," says Andrew Derocher, a professor of biological sciences at the University of Alberta — but let’s call him a "polar bearologist," since he’s been studying this animal for nearly 40 years.
Derocher started studying the western Hudson Bay population of polar bears in 1984 before going off to the Norwegian Polar Institute. In 2002, he was hired by the U of A and has since studied them across the Canadian Arctic.
Discouraged by pandemic travel restrictions hindering his research, Derocher was able to monitor when the bears left the sea ice over the summer using radio collars. It was well into July this year when the first bears came ashore, and that is great for the bears’ health, he explains.
"It’s a really good situation," he says. "Longer term, it doesn’t change our concerns about the conservation of the population, because as climate change continues, we’re going to see shorter and shorter ice-cover periods. But this really looks like a good year for the bears."
In bad years he’s seen the bears coming off the ice weeks earlier, at the beginning of June.
"They come ashore with enough fat to easily go 130, 140, even 150 days without having any significant impacts on their likelihood of survival. But once you start getting out beyond 180 days or so, now you’re asking every bear that comes ashore to have somewhere around 150 to 200 kilograms of fat to deal with that fasting period. And not all bears are coming ashore with enough reserves. Usually the ones that run out are the very young and the very old. And that’s where we see these long ice-free periods increasing the mortality," Derocher says.
Research co-authored by Barber and published in Elementa: Science of the Anthropocene in 2018, demonstrated that Hudson Bay went from a median number of 130 ice-free days between 1981 and 1985, to 149 days between 1996 and 2000. Between 2010 and 2014, it was 155 days. And with a median at 155, there are years that are well in excess of that number.
Derocher was able to monitor when the bears left the sea ice over the summer using radio collars. SUPPLIED PHOTO
Across the Arctic, all of the last 14 years rank as the lowest sea-ice years recorded since tracking began in 1979, according to the U.S. National Snow and Ice Data Center.
So it was with great relief that Derocher watched this one population of bears doing well this year.
There are several estimates for the size of the western Hudson Bay polar bear population and how it’s changed over time.
Derocher’s research indicates that in 1987 the population was approximately 1,185, which fell by 32 per cent to 806 bears by 2011.
In 2018, the Government of Nunavut reevaluated its quota on the number of bears that could be hunted based on estimates that the size of the population in western Hudson Bay stood at 842 bears, down by 18 per cent from its estimate of the population in 2011, which was 1,030 bears.
Environment and Climate Change Canada’s estimates are slightly different: 1987 (1,194 bears); 1994 (1,233 bears); 2005 (935 bears); and 2016 (842 bears).
How fast and how far the population size will drop is still being debated, but researchers tend to agree the future is bleak for the animals and it’s just a matter of how bad and how soon.
"With high greenhouse-gas emissions, steeply declining reproduction and survival will jeopardize the persistence of all but a few high-Arctic subpopulations by 2100," the article states.
Much of the uncertainty of the safety of the polar bears has to do with no way to gauge at this point how successful humans will be at curbing global greenhouse-gas emissions and slowing the process of climate change.
Nick Lunn, a research scientist with Environment and Climate Change Canada, still remembers the first time he handled a polar bear. It was a brisk day, Oct. 10, 1981.
"I’d just come up to help a graduate student do some research and we landed at the airport and the fellow came rushing into the airport to grab me because they’d just immobilized a bear and they were working on it just behind the airport. So I didn’t even have time to change into field clothes," Lunn says.
Environment and Climate Change Canada research scientist Nick Lunn weighs a polar bear cub in spring. SUPPLIED PHOTO
While he has handled hundreds, if not thousands, of bears in the time since, he says it remains an incredibly special experience. He can’t imagine another job he’d ever want to do.
Every fall, he travels to Churchill from his home base in Alberta and he works with his team to capture and take measurements and biological samples from at least 100 bears in Wapusk National Park southeast of Churchill.
New information is plugged into one of the most comprehensive data sets available for any polar bear population in the world, with consecutive-year input collected since 1980. That is, until this year, because of COVID-19 travel restrictions, the data set will miss its first year of collection in the 41-year unbroken chain of data.
While it wasn’t originally collected with the intention of it being used to understand demographic shifts in a changing climate, that is what it has become.
Lunn says there are a couple of key takeaways, such as the fact that over time the average weight of bears is declining. Using solitary adult females as an example, over the last 40 years, they’ve become approximately 40 kilograms lighter, on average.
Weight is a good proxy for understanding the health of the population, Lunn explains, because of how this population relies on its fat stores to get them through the summer and because of how much longer the ice-free period is becoming. With extra weeks tacked onto their fasting period in the spring, it is not surprising that by September the bears weigh much less, and then also have to wait longer for the fall freeze-up.
But the biggest stress is on mothers travelling to shore to birth their cubs, Lunn says, because the don’t go back out onto the sea ice in the fall with the rest of the bears. They are in dens, where they give birth to their cubs, and don’t return to the ice until February or March.
"They’re on shore for upwards of eight months or so," he says. "And, as I said, they’re now at 40 kilograms less over the last 40 years. So for them, that impacts the size of their cubs… and smaller cubs have lower survival rates."
Mothers’ fat stores have to provide not only for their own fasting period, but also for the cubs to continue nursing throughout the summer.
“I’d just come up to help a graduate student do some research and we landed at the airport and the fellow came rushing into the airport to grab me because they’d just immobilized a bear and they were working on it just behind the airport. So I didn’t even have time to change into field clothes.”
— Research scientist with Environment and Climate Change Canada, Nick Lunn, on the first time he handled a polar bear
Lunn says over the same 40-year period, the survival rate of triplets has all but disappeared. At one time, two to three per cent of the bears caught were triplets, but 1996 was the last time evidence of triplets surviving until the fall was seen.
"And we think that’s linked to lower cub survival," he says. "That means at least one, if not more, aren’t surviving through to the fall. (Triplets) are there in March, three months old. They’re not there in September when they’re nine months old."
Despite the reprieve for Churchill’s bears this year, Derocher watched the ice season in other parts of the world with worry. He predicts that Russia polar bears — the Laptev Sea population — are likely to be hit hard this year, he says, given the extraordinary heat waves that took place resulting in a significantly shorter ice season, as well as forest fires across Siberia.
The problem is there are no monitoring programs in place for that population, so answers as to the effects will be scarce.
"One of the things we’re concerned about, and might happen, is that it would only take one or two really bad years for a population to really be set back," Derocher says.
"We’re just seeing the slow erosion in the population (in western Hudson Bay), we’re not getting these devastating years, and by devastating, I mean we could lose 30 to 40 per cent of the bears in a single year if we got one of these really early break-up years."
“One of the things we’re concerned about, and might happen, is that it would only take one or two really bad years for a population to really be set back.”
— Andrew Derocher
If an event similar to the Siberian heatwave occurred over western Hudson Bay, "it could be that maybe the bears come off in May. And now what you have is 800 bears, none of which are doing well, many of which are starving, unlikely to survive, many more bears coming into town than you would ever be able to deal with."
The question would become: What do we do about it? Derocher says it’s a scenario we are not currently prepared for.
He foresees a time where conservation agencies will be presented with choices between euthanizing bears, moving them, or even airlifting in food caches to get the populations through the hard times. But any of those options would be Band-Aid solutions, lowering emissions is the only means of saving the species in the long term, Derocher says.
Lunn echoes Derocher’s concern over a potential devastating event knocking the population down. Devastating events have particularly dire consequences for animals that don’t reproduce at high rates and are long-lived. Bears would take decades to recover, if they ever did, if something like that were to happen, he says.
Locally, and even more prominently in coastal communities in Nunavut, people have questioned the veracity of scientists’ claims that the polar bear population is declining there, as people are coming into contact with bears more often. In 2018, two people were killed by bears in Nunavut.
However, scientists explain this seemingly contradictory information by looking at bear behaviour in bad ice years. Despite the fact that bears are supposed to be fasting when they’re on land, Derocher says, in a short-ice season when they come off the ice without enough fat stores they’re going to go looking for food. Urban areas offer a convenient one-stop shop.
Derocher on bear behaviour in bad ice years: "There’s great potential that they could become much more dangerous for local residents." SUPPLIED PHOTO
"We know this population has been declining over time, and yet in some years we see very large spikes in the number of problem bears," Derocher says. "Fat polar bears that are well fed, just aren’t going to be a problem. The concerns that we have is that as climate-change effects are being felt in the population, there are more individual bears that are not in good condition, and those bears just don’t act the same as a big, fat bear."
"Hungry bears are desperate bears and they will do almost anything to try to stay alive. And if that means going into a community to try to hunt or scavenge, they’ll do that. That becomes the real problem. It’s no longer the same animal that you’re used to seeing. So there’s real concern that we’ll see these shifts in the behaviour of these bears going forward. There’s great potential that they could become much more dangerous for local residents."
Learning more about the bears that end up becoming a problem is an ongoing thread of research. If a bear is flagged on multiple occasions near or in Churchill, it ends up in "polar bear jail" — Manitoba Conservation’s holding facility. Derocher says at that point Manitoba Conservation will put a radio collar on the animal that allows it to be tracked after it is flown north and dropped off further away from humans.
"A lot of the bears are just passing through," Derocher says. "Churchill is on this migration route. It’s almost accidental that they get into trouble."
The radio collars allow the bear to be tracked to see if it is heading back towards Churchill, so it can be intercepted. It also allows researchers to see if the bears that are being dropped off further north in Manitoba are becoming problem bears in Nunavut communities. Derocher says the evidence doesn’t suggest that’s the case.
"Hungry bears are desperate bears and they will do almost anything to try to stay alive. And if that means going into a community to try to hunt or scavenge, they’ll do that. That becomes the real problem."
— Andrew Derocher
"They definitely are getting bears that have been near Churchill, but it doesn’t seem that the ones that are causing problems around the town of Churchill are necessarily the ones that are going to cause trouble up in Arviat, for example," he says.
Meanwhile, some sort of community alarm or warning system has been in the works for years. "Any early warning in communities is always going to be beneficial," Derocher says.
"Because we are seeing bears spend more time on land across the Arctic and increasing conflicts with humans, and so having some sort of ability to at least detect some of the animals coming in is going to be a benefit. The problem is a lot of these communities are very small (and) the equipment isn’t cheap; it requires someone to be monitoring it, to some degree. But the intent of it is to have it go to the RCMP in some of these small communities or wildlife (conservation workers) would get a text or an alarm that there’s something moving through the community."
This community safety feature is unfortunately still a few years away, he says.
In 2006, Time magazine published a photo of a polar bear stranded on an ice floe under the headline, "Be worried. Be very worried." The years since have only further cemented the polar bear’s place as the icon of the climate crisis. And yet, there is no progress on saving the animals. Global greenhouse-gas emissions continue to rise, perhaps slowed only ever so briefly by the global pandemic. The devastating blow to the world’s rich fabric of biodiversity is on course.
Lunn says he thinks that using polar bears as an icon for the problem is a positive thing. It gives people something beyond particulate matter in the atmosphere to latch onto — the beloved bears help people understand the magnitude and consequence of the loss of biodiversity the world is facing.
"Polar bears are something people can readily identify," he says.
"They’re cute and cuddly. So I think it’s helped the discussion a lot, to at least make people aware, and I think that’s probably the key. The critical thing to me is that we’re not just talking about polar bears, yes, that gets peoples’ attention. But we’re really talking about an Arctic marine ecosystem that is impacted by climate change and these ecosystems are linked. It’s a single planet.
"So yes, things are happening faster in the polar regions, but it doesn’t mean that things won’t happen elsewhere."
This article was a part of a 16-part series published in the Winnipeg Free Press titled Bearing North: An Exploration of Climate Change’s Impact on the Churchill Region. Read more of the series here.