In a recent study, researchers attached video cameras and GPS collars to 20 polar bears in western Hudson Bay, Canada. They monitored their behavior and energy expenditure during the summer months when the ice melts. And the news isn’t good. Based on the footage, the researchers concluded that the bears are rapidly losing weight and starving due to longer periods spent on land as a result of climate change.
While scientists initially hoped the bears might adapt to ice-free seasons by foraging for land-based food, the study, published in Nature Communications, paints a different story. Despite resting, scavenging, and foraging, almost all bears lost weight rapidly, averaging 2.2 pounds per day. This is concerning, as these reserves are crucial for surviving the long winter when hunting seals on ice becomes possible again.
“Neither strategy will allow polar bears to exist on land beyond a certain amount of time. Even those bears that were foraging lost body weight at the same rate as those that laid down,” said Charles Robbins, director of the Washington State University Bear Center and co-author of the study. “Polar bears are not grizzly bears wearing white coats. They’re very, very different.”
Why can’t polar bears adapt?
Compared to their grizzly bear cousins, polar bears are larger and nearly two times heavier. They’re specialized for hunting seals on ice, and they need them as energy-rich food. Their bodies are not efficient at processing land-based food, and scavenging or foraging for berries and plants expends more energy than it provides.
The footage showed that three desperate bears attempted long swims in hopes of finding food. One of them went as far as 175 kilometers (about 110 miles) across the bay. While two found carcasses, they were unable to access them while swimming or bring them back to land.
Even though the study focused on the southern Hudson Bay population, the researchers warn that polar bears across the Arctic are at increased risk of starvation. This will particularly hit younger bears and mothers with cubs. And in Hudson Bay, climate change seems to hit the hardest at the moment. The polar bear population in this region has already declined by 30% since 1987, according to the Washington State University press release.
This research highlights the urgent need to address climate change and protect polar bear habitat. By reducing greenhouse gas emissions and taking steps to conserve sea ice, we can help these impressive animals survive. Or we’ll end up with yet another extinct species.
[via PetaPixel]
