The proof is in the polar bear poop! Or, at least the clues are there. In the first study of its kind, researchers from Dalhousie University compared scat from captive and wild polar bears to determine what effect dietary changes could have on their microbiomes (a strong indicator of both nutritional and overall health).
As sea ice dwindles in the North — a roughly 18 per cent loss from 1982 to 2020 — polar bears will have to rely less on their traditional fatty diet of seals and more on a low-fat, high protein diet characteristic of food they find on land. This could lead to a higher risk of bears not meeting their nutritional needs and possibly starving.
With the help of the Churchill Northern Studies Centre, researchers analyzed scat from wild bear populations, both offshore — bears that live mostly on ice and prey on seals year-round — and onshore — bears that rely on seals during the winter, but survive off body fat stores during the ice-free season. Scat from captive bears were taken from four animals, named Henry, Ganuk, Inukshuk and Eddy, housed at the Cochrane Polar Bear Habitat in Cochrane, Alta. According to the university, the captive bears were fed “a higher protein mackerel-based diet, simulating the habitat and lifestyle changes wild bears may be forced to undertake should they become landlocked.”
Perhaps unsurprisingly, their findings showed distinctly different gut microbiomes between the captive and wild populations, in line with the variations in their diet. Researchers hope these findings will help shed some light on the implications of climate change on this species’ access to food and, ultimately, their survival.