Understanding the changing dietary habits of polar bears is the key to seeing how climate change and shrinking polar ice is affecting their lifestyles. And the best way to know what’s happening with their diet? Look at their poop, of course! Linda Gormezano, an ecologist at the American Museum of Natural History in New York City, has trained her dog Quinoa to help her find the best samples left by bears as they cross the frozen Canadian tundra. Gormezano chatted with us about why poop is such a useful scientific specimen and what it’s like to spend months living in a camp in the heart of polar bear country.
What’s ecology and how does it apply to polar bear research?
Ecology is the interaction between animals and the environment. What we’re studying is how polar bears behave on land with respect to available food -- what they eat and where they eat it. What I’m particularly interested in is how they hunt other animals and how the calories they gain from consuming them are going to affect their annual energy budget as their access to ice becomes more limited.
We collect scat and hair samples non-invasively. After consuming food on the ice or on land some bears leave scat. Also some bears rest right along the coast, bedding down in sand and grass where they leave hairs behind, while others head further inland and leave hair in dens.
What, exactly, is an energy budget?
Nobody really knows how often polar bears in western Hudson Bay capture seals, but they get a certain amount of energy from consuming seals they hunt out on the ice and that energy allows them to survive on land for 4-5 months each year. If the ice melting earlier each year causes polar bears to have less time to hunt seal pups in spring, they may be taking in fewer calories over the course of the year.
What we want to know is, now that they’re eating more of certain types of foods on land, what kind of energetic benefits might polar bears be experiencing? Up until now many have thought what they were eating on land wasn’t really helping them at all. To evaluate this, we are examining the energetic costs and benefits of capturing and consuming those foods as well as how often the behavior occurs. Only then can we determine whether these foods could help alleviate nutritional deficits that polar bears may come ashore with.