|credit: R. Rockwell|
The exact energetic cost of polar bear hunting land prey is not yet known however; nowhere in the scientific literature is it documented that polar bears are shifting to a terrestrial diet in general. Caribou herds continue to forage near the coast of Western Hudson Bay, and are apparently unaware of the bears changing hunting behavior. Snow geese eggs are a good source of protein and require little effort to take from their ground nest. Snow geese are know to endure egg predation by polar bears, but in a study published in April, scientists observed fewer than thirty bears within populations of 900 to 2500 individuals consuming terrestrial foods such as eggs. Further, starving polar bears with a higher energy requirement will have to compete with other predators such as brown bears that are already adapted to surviving on scarce Arctic food sources. So some polar bears will survive the heating of the Arctic, if they live in an abundant ecosystem and are opportunistic. Many more will not. The chief scientist for Polar Bear International agrees with the scientific consensus that without greenhouse gas mitigation the polar bear will be extinct by the end of the century.