The news has been flooded by warning about the accelerating loss of ice in the Arctic regions – reaching its lowest maximum – that causes worrying signs of rise in sea levels. However, according to a study from the journal Frontiers in Ecology and the Environment, that’s not the only harmful side effect.
Apparently, less ice also means less frozen habitable land left for polar bears – a change that has deep consequences on how they find their supplement of marine animals. Instead of fishing from the water, polar bears are forced to turn to the land, but this low-fat terrestrial diet, mostly made up of birds, eggs and berries, doesn’t come even close to replacing their satisfying diet of fat-rich seals, for example.
Lead author Karyn Rode, a wildlife biologist from the U.S. Geological Survey, gave a statement explaining that polar bear survival rates have been on the decline in the areas where they were forced to adapt to terrestrial feeding. Such reports offer experts invaluable insight into the ecology of bears on land.
Previous theories believed polar bears will learn to adapt to their changing environment, as sea ice thins in the Arctic, and that hunting on land will become a survival technique.
However, latest discoveries show exactly the opposite, suggesting that goose eggs, plants and berries are not enough to satisfy the polar bear’s high lipid diet. Food found on the land is mostly high in protein and low in fat, so the bears are in danger of starving.
Rode added that bears have been spotted eating terrestrial food, but so far, no evidence was found to support the idea that this behavior is gaining traction. As stated in the study, less than 30 polar bears were monitored eating bird eggs.
The biologist explained that, in spite of the publicity showing polar bears consuming eggs, it is a behavior far from being common in the communities. The fact that so few specimens have adopted this eating habit suggests little population-level impacts on polar bears’ survival.
Steven Amstrup, co-author of the paper, illustrated the new behavior more like a survival technique than a successful adaptation to an iceless land. It’s like humans eating either some lettuce or a steak; both might fill our stomachs, but just one will give us the necessary energy to go for the day.
Another dangerous side-effect to the thinning ice is the fact that the more polar bears turn to eating bird eggs in order to sustain themselves, the more harm they bring to other species. If this behavior becomes widespread, the polar bear’s dietary needs might decimate the Arctic seabird population.
Image Source: Polar Bear Endangered
