Busy Times at the World’s Largest Polar Bear Prison

In the town of Churchill, Manitoba, there’s a huge, gray, three-humped hangar, containing cages made of reinforced cinder blocks and thick metal bars. It’s a jail for polar bears. And when its cells start filling up, you know something is wrong.

Churchill sits on the western flank of the Hudson Bay, which is home to around 800 polar bears. The town was actually built on the bears’ migration route, and many of the huge predators skirt the town’s borders. “It’s unnerving, walking around,” says Andrew Derocher from the University of Alberta. “You walk out in the morning, and from the tracks in fresh snow, you see that a bear has walked between the houses.”

Townspeople used to just shoot the bears, but if anything, that worsened the conflicts between the two species. Following a series of attacks in the 1960s, culminating in the death of a child, Churchill started developing a better system.

Now, when people spot a bear, they call 204-675-BEAR. The 24-hour hotline reaches the staff of the Polar Bear Alert Program, who have divided the area around Churchill into three concentric zones. If the bear’s in the outer zone, the staff will try to scare it away by firing cracker shells—shotgun rounds that explode with especially loud bangs. If that doesn’t work, they resort to rubber bullets or paint balls.

If the bear is in the inner zone, where Churchill residents live and work, the staff will try to capture it. They do that with large cylindrical traps, baited with seal meat. When the bear enters, it triggers a metal screen, which locks behind it. And since the traps are mounted on the backs of trailers (like the one from the third Indiana Jones film), the bear can be immediately driven away to the Polar Bear Holding Facility.

Built in 1982, the facility has space for 28 inmates, and has held over 2,000 to date. It’s not a long-term prison. Bear families are relocated as soon as possible. If they capture a lone bear in the inner zone, they keep it in jail for a month, to minimize the chance that, once released, it’ll just go back to the same place. When the time is right and the weather clears, the wardens tranquilize the animals, bundle them in nets, strap them to helicopters, and airlift them to a site 70 kilometers north of Churchill. The bears get ear tag radios so that officials can track their movements, and lip tattoos so they can be identified in future years.

The Polar Bear Alert Program has been a tremendous success, for both bears and humans. From a site of fatal conflict, Churchill has become a symbol of co-existence—not to mention a major tourist destination for people keen to see and photograph the bears.

But conflicts are becoming increasingly common. This year, the program staff have so far responded to 386 calls to their hotline—the busiest on record. More bears are encroaching into human spaces, and not just in Churchill. People in Alaska, Norway, and Greenland are seeing the same trend. Earlier this week, a polar bear was killed after wandering into Tuktoyaktuk, Canada; it was the town’s third sighting since September, after a decade of no contact.

These conflicts can be managed, but they are the harbingers of a more unsettling trend. The Arctic is changing, affecting even places like Churchill which lie further south. The ice the bears depend on is disappearing. And the bears are struggling.

The polar bear is a machine for converting seal fat into bear flesh. To capture ringed and bearded seals, it needs ice. So in the spring and summer, when ice melts and disappears, the bears move on shore and enter a long fast. They burn a kilogram of their own fat every day while they wait for the ice to return. In Churchill, this used to happen in early November. “It would get cold, a storm would come in, the ice would spread like gangbusters, and the bears would disappear.”

But this year, the big freeze has been delayed. Visiting in November, Derocher wrote, “I was stunned by how warm it was.” Some parts of Hudson Bay were 10 to 20 degrees Celsius warmer than usual. When the sea ice formed, it soon melted again in, expanding and contracting in an abortive stutter. By the end of November, most of the bay was still ice-free. The bears, instead of stalking out across solid whiteness, were left gazing at endless blue. Only in the last week has there been enough ice for them to head offshore in search of seals.

The late freeze is coupled with an increasingly early thaw, which means that the bears spend less of the year hunting. Come the summer, their fat reserves are lower than usual, and they have to spend more time feeding off those reserves. Some starve to death. Others explore alternative sources of food, including other bears, killer whale leftovers, and human trash—hence, the growing number of calls to the Churchill hotline. Pregnant females abort their cubs. Those that already have cubs can’t find enough food for them. The entire population enters a tailspin. The west Hudson Bay used to have 1,200 polar bears. There are now just 800, and the decline shows no signs of slowing.

The changes are visible to anyone who has been visiting Churchill for three decades, as Derocher has. In the 1980s, polar bears were everywhere. “You could catch a bear and you never had to look for another one,” he says. The bears were huge too—roly-poly animals, rotund with stored fat. Gorged on seal fat, mother bears could get away with raising three cubs, and they could successfully wean each one at 1.5 years of age.

Now, Derocher says the bears are rarer and skinnier. He hardly sees any mothers with more than one cub, and the cubs rarely survive past their second year. Cannibalism is on the rise: the last bear that Derocher saw was “an incredibly skinny male who was burying a cub that he had killed.” His colleagues also found two cubs wandering about on their own. “Mothers don’t give up their cubs so maybe mum was killed by another bear,” he says. “The likelihood of them surviving is nil.”

Derocher and his mentor Ian Stirling predicted all of this way back in 1993, in a paper entitled “Possible Impacts of Climatic Warming on Polar Bears.”

“In retrospect, the opening line—If climactic warming occurs…—was naïve because the climate was already warming,” he says. “But at the time, I thought this was a long time away—something for future generations of polar-bear scientists to look at. We didn’t understand how fast the Arctic would change.”

Geoff York from Polar Bear International agrees. “I fear I saw a new normal unfold before my eyes,” he wrote, after visiting Churchill in November. “I fear this is the beginning of a phase change, a shift—a consequence of both our actions and inactions to date.”

Scientists who study the climate and weather of the Arctic, and not the animals who live there, have noted a similar shift. Sea ice has done some extremely odd things in 2016. In March, when northern sea ice normally covers the broadest extent of the Arctic Ocean, it set an all-time record low. In September, it tied the second lowest-ever summer record. Even now, less than a week from the solstice, it has barely recovered. Experts who have visited what sea ice does exist say it is unusually thin.

This is in part because climate change is reshaping the Arctic faster than the rest of the planet. In its Arctic Report Card 2016, released this week, the National Oceanic and Atmospheric Administration noted that Arctic air temperatures are increasing twice as fast as those in the temperate regions. The entire region’s temperatures are 2.5 degrees Celsius warmer than they were at the start of the 20^th century. In the Arctic, where so much depends on the freezing point, these elevated temperatures are cataclysmic.

The whole ecosystem is changing with it. According to a new study, published last week, there’s a 71 percent chance that the global polar bear population will fall by over 30 percent in the next three decades. The probability that its population would be halved was much lower. Because of this, the IUCN Red List continued to rule the species vulnerable, but not endangered.

In a talk at the annual meeting of the American Geophysical Union, an author of the study warned on Tuesday that its methods contained a lot of uncertainty. For his part, Derocher believed the top-line estimate was “overly optimistic.”

The only hope for the polar bear is to reduce carbon emissions, in the hope that the runaway pace of Arctic warming will eventually stabilize and reverse. It’s a dire situation, which is forcing people like Derocher to consider extreme solutions—like feeding the surviving bears. That’s a highly controversial step, but one that has proven successful for grizzlies in Europe, elk in Yellowstone, black bears in Washington, and more. “This would be a last effort to keep polar bears in the wild to nurse them through a period of warming before the planet cools again,” says Derocher. “We’re better off having a semi-wild population of animals than keeping them in a zoo and reintroducing them.”

The Churchill bears, however, are probably doomed. “There are several populations that will disappear no matter what policies are put into place,” says Derocher. The hotline is ringing steadily now, but it will soon lapse into silence. The tourists will stop coming. The bang of cracker shells won’t be heard. Helicopters won’t fly overhead with white sedated balls of fur dangling below. And polar bear jail will go unused. When its cells go forever empty, you’ll know that something’s really wrong.