More than any other keystone species, the polar bear is directly threatened by climate change. So the goal of conservationists is to try to keep their numbers high enough over the coming decades that we may still have a viable population when, or if, sea ice levels can be returned to normal. The latest solutions in that fight? Jails and radar stations.
To recap, polar bears survive by hunting seals on frozen sea ice above the arctic circle. But as that area of ice and the portion of the year when it remains frozen both continue to shrink, the bears find it harder to hunt. This is causing their numbers to plummet, while conflicts between bears and humans increase, which can reduce their numbers even further.
The Western Hudson Bay population—one of 19 worldwide—has seen its numbers fall from about 1,200 in 1998 to just 842 today. Those are the bears that gather every fall near Churchill, Manitoba, waiting for the ice to reform so they can return to sea. There, a town of 900 hosts 10,000 visitors who come to see that migration. But as bears must wait longer for the sea ice, they’re motivated to seek out alternative food sources in town. And that leads to trouble.
“The population is decreasing, but conflict is increasing,” says Andrew Derocher, a scientific adviser to Polar Bears International. “This seemingly contradictory scenario is entirely consistent with nutritionally stressed bears spending longer periods of time on shore.”
Traditionally, the method for reducing conflicts between bears and humans was simply to kill more bears. And the annual quota of bears that the Inuit hunters in nearby Nunavut, which shares the same bear population, are able to take is a hotly debated topic. As polar bears become more stressed by decreasing access to sea ice, it’s also becoming less certain that hunting them has a meaningful impact on conflict, all while bringing that population closer to the brink. So experts are looking for new solutions.
One of those solutions is polar bear jail. In Churchill, bears that enter town in search of food are sent to the slammer, where they’re held in cages with minimal interaction and without food until the sea ice starts to reform and the bears can once again hunt seals. Then they’re transported by helicopter northward, onto the sea.
“The idea is to not reward their behavior but to discourage it,” Derocher says. The bears typically fast throughout the summer anyway, and by keeping them safe until they can hunt for food, wildlife management officials are making sure they don’t reinforce any connection between humans and food sources.
The problem was that, until 2017, it was hard to convince residents that the program was effective. Wouldn’t hungry bears transported a short distance northward simply enter other towns for food instead? Existing tracking technology relied on bulky GPS collars that could be fitted only to male bears—female heads aren’t big enough to prevent the collars from slipping off. A smaller ear-tag tracking device was later developed that could be used on any bear. Derocher says it’s too soon to draw definitive conclusions, but early signs indicate that the program is successful: Bailed-out bears are returning to the sea ice as intended, rather than continuing to pester human settlements.
But a successful polar bear jail means having to find those bears before they can enter town and create a connection between humans, the places they live, and tasty stuff to eat. Until 2018, early detection of bears relied on human patrols. With growing nutritional stress due to the increased loss of sea ice, the number of bears attempting to enter Churchill was getting out of control—2016 saw 300 bear response calls in a town that numbers just 900 people. A better means of detection—and one that would work at night or in adverse weather conditions—was needed. Enter radar.
Like GPS tags, radar is another technology that’s become drastically smaller and more affordable in recent years. SpotterRF, a Utah-based defense contractor, makes small, portable ground radar units intended to detect human intruders around sensitive places like power plants and data centers. The radar units themselves are about the size of a telephone book, and prices start at about $30,000. With the help of Salt Lake City’s Hogle Zoo—famous for its underwater polar bear viewing—Polar Bears International was able to raise the funds necessary to install a bear-monitoring radar unit on the roof of the town’s community center.
Detecting bears approaching across the tundra requires teaching the software that runs the radar to learn the difference between, say, a human riding an ATV and a large predatory mammal. The software can learn to dismiss fixed objects like rocks and can be taught to recognize the size and movement patterns of different animals. Polar Bears International is able to monitor these functions remotely from its office in Bozeman, Montana, where it compares them against security camera footage and is slowly training false positives out of the system. Meanwhile, bears that are detected approaching town can be scared off with nonlethal deterrents or, if they persist, captured and thrown in jail.
The goal isn’t simply to reduce conflict between bears and humans around Churchill, but to develop systems and practices that can be employed by other communities throughout the arctic. The bear-detecting radar, in particular, holds promise for smaller communities that can’t afford a full-time bear patrol. The hope is that human-bear conflict can become more manageable, even as climate change is causing hungrier bears to spend more time on shore. And providing communities across the arctic with the ability to manage that conflict with nonlethal means may reduce the number of bears the communities kill. Later this century, if we are able to take meaningful action on climate change, these technologies could help ensure that we have enough polar bears left to repopulate the arctic.
“Science can’t save polar bears, but it can help both the people and the bears find a way to smooth out their relationship in a changing arctic,” Derocher says. “We owe it to the people who live day to day with polar bears, and the bears themselves, to find smarter ways to coexist.”