These polar bears appear to be maintaining their physical health despite the loss of sea ice—their preferred hunting grounds

Polar bears need fat to survive the harsh Arctic cold; that’s why they eat blubbery seals. Seals, meanwhile, need ice to rest and birth pups. Without that ice, polar bears have a hard time finding and catching them.

As the planet warms and sea ice melts, the prediction has been that polar bears would have a harder and harder time finding food, and would begin shedding pounds. So, weight gain in the population is a cause for celebration.

In the frozen wilderness of the Arctic, human survival historically depended on using every available food source. But one part of the polar bear hides a dangerous secret that has proven deadly to people for centuries: its liver.