Starving polar bears may some day have to look inland for food, which could make them a danger to humans, says a Dalhousie University biologist.
Sara Iverson said climate change is putting polar bears in danger. The bears depend on ice flows to feed off of seals in the winter. As the spring comes, the ice melts and the bears move inland. They’ll then fast for as long as eight months until the ice reforms.
But in recent years the ice has melted early, forcing the bears inland before they have built up enough fat reserves.
“It’s critical that they are able to get that level of fat storage. But if they’re forced ashore earlier they’re going to be in poor condition and much less likely to survive that fast,” said Iverson.
“They’re also going to be looking for other food sources, maybe terrestrial kinds of food sources. There’s also the problem with interacting with human communities.”
Iverson will deliver a public lecture on her research as part of the Canadian Society of Zoologists 2008 Annual Meeting happening this week at Mount Saint Vincent University. The lecture takes place this evening at 5:30 at the Seton Academic Centre.
Iverson has been researching the top predators in arctic environments to see the effects of the entire ecosystem. While these ecosystems are extremely complex, scientists can determine a lot by looking at the animals at the top of the food chain.
Her team has been analyzing the diet of polar bears through fat samples, and discovered that their usual seal diet has become more diverse as they try to adapt to changes in conditions.
“It’s a scary situation. Ice-dependent species are really the species of most concern,” she said. “(They) are really the canaries in arctic coal mines.”
Iverson said more polar bears may enter human communities as they look for new sources of food.
Recently the United States listed polar bears as a threatened species. Canada lists them as a “species of special concern.”
-paul.mcleod@metronews.ca
