© Kt Miller/Polar Bears International
2/25/2015 2:35:24 PM
New Study Helps Scientists Understand Polar Bear Diets
It used to be that polar bears ate mainly one thing-seals. Maybe they'd munch a little kelp while waiting for sea ice to form or chow down on a beached whale, but the bulk of their nutrition and sustenance came from seals.
The times they are a changing. As global warming causes sea ice to form later in the season and melt earlier, polar bears are having a tougher time hunting seals. Scientists want to understand if and how polar bear diets are changing.
Polar bears are difficult to study in the wild. Now though, Conrad and Tasul, a pair of bears at the Oregon Zoo, have given researchers a never-before-available tool for tracking the feeding behavior of their Arctic cousins.
Over the past several years, Karyn Rode, a wildlife biologist with the U.S. Geological Survey's Alaska Science Center and her team have been developing a method for tracing the chemical composition of Arctic polar bears' prey - to see what the bears have been eating and when.
Rode was able to refine this method by studying the captive bears at the Oregon Zoo.
"Our findings at the Oregon Zoo will let us use decades of archived blood samples from wild bears to determine if - and how - diets are changing in response to sea ice loss and other factors. The ability to learn from Conrad and Tasul's (the zoo bears) behavior and physiology is extremely valuable to understanding polar bears in the wild," Rode said.