New research suggests Arctic polar bears may be forced to turn to alternative food sources as a result of the warming climate.
Polar bears' preferred food source are ringed seal pups, but ice that "melts earlier and freezes later" than it used to has significantly shortened their hunting season, an American Museum of Natural History news release reported.
The team found polar bears in the western Hudson Bay population have taken up a diet of mixed plants and animals.
"There is little doubt that polar bears are very susceptible as global climate change continues to drastically alter the landscape of the northern polar regions," Robert Rockwell, a research associate in the Museum's Department of Ornithology, said in the news release. "But we're finding that they might be more resilient than is commonly thought."
Polar bears are considered to be threatened under the United States Endangered Species Act; they have also been classified as "vulnerable" under the International Union for Conservation of Nature and Natural Resources' Red List.
These bears are meant to gain most of their fat reserves from seal pups during the spring months before coming ashore, but their shrinking ice habitat has been making this difficult.
The new study "examines how polar bears might compensate for energy deficits from decreasing seal-hunting opportunities," the news release reported.
Researchers captured footage and collected the first data of polar bears eating juvenile snow geese during the mid to late summer season. The team also looked at the polar bears' scat to determine the Hudson Bay bear population has a different diet than it did 40 years ago. The scat contained more evidence of caribou and geese consumption than it would have before climate change started affecting the region.
The analysis found there was little geographic movement during the hunting season, meaning the animals were keeping their energy expenditure at a minimum.
"For polar bear populations to persist, changes in their foraging will need to keep pace with climate-induced reduction of sea ice from which the bears typically hunt seals," Linda Gormezano, a postdoctoral researcher in the Museum's Division of Vertebrate Zoology said in the news release. "Although different evolutionary pathways could enable such persistence, the ability to respond flexibly to environmental change, without requiring selective alterations to underlying genetic architecture, may be the most realistic alternative in light of the fast pace at which environmental changes are occurring. Our results suggest that some polar bears may possess this flexibility and thus may be able to cope with rapidly changing access to their historic food supply."
