A recent study published in the journal PLOS ONE suggests that polar bears in the western Hudson Bay could find enough food to survive on land as ice-free periods grow longer, according to Science Daily.
“Climate change is predicted to expand the ice-free season in western Hudson Bay and when it grows to 180 days, 28–48% of adult male polar bears are projected to starve unless nutritional deficits can be offset by foods consumed on land,” states the study abstract. Previous models assumed no caloric energy gained from food sources on land. The study’s authors, Linda Gormezano and Robert Rockwell, from the American Museum of Natural History (AMNH), estimated the energy required to offset starvation and concluded that caribou, snow geese, and snow goose eggs could provide enough calories to sustain polar bear populations.
The ice-free season in the western Hudson Bay is expected to expand to 180 days by 2068. Even then, polar bears might find enough food to survive for extended periods of time separated from sea-ice hunting grounds. “Polar bears are opportunists and have been documented consuming various types and combinations of land-based food since the earliest natural history records,” said Rockwell in material released by the AMNH. Adult bears have been observed ambushing caribou in a manner similar to how they hunt seals, preserving as much energy as possible and catching similar-size prey. The researchers also point out that gathering snow goose eggs is particularly low-energy.
“Analysis of polar bear scats and first-hand observations have shown us that subadult polar bears, family groups, and even some adult males are already eating plants and animals during the ice-free period,” said Rockwell.