Polar bear pal Luana has stopped by the Wild Wire to tell us what itâ€™s like being a scientist studying the worldâ€™s largest land carnivore! Listen up to hear a tale of taking to the skies to explore the Arctic, collecting fat samples and, of course, cuddling baby Polar bears.
Spotting the Great White Bear
Thereâ€™s a little game I like to play while flying through the clear blue skies above Churchill, Manitoba. Itâ€™s called â€śWhereâ€™s Waldo?â€ť But itâ€™s not Waldo that Iâ€™m looking for. Instead Iâ€™m keeping my eyes peeled for the largest living land carnivore on Earth. The Polar bear can sometimes weigh nearly 1,000 pounds, and from the plane I can see them walking slowly across the open tundra or ice covered Hudson Bay. At first thought, you might say that an animal this large should be easy to spot, but in the cold winter months with huge cliffs of ice and snow covered ground, the Polar bear is much more difficult to find than you might think! Their white coat keeps them very well hidden, which means we must fly for hours looking for their tracks in the snow and keeping our eyes peeled for this great bear of the North!
Studying Polar bears in their natural environment is exciting! My research with Dr. Nick Lunn from Environment Canada is helping to answer some very important questions about how the bears in Western Hudson Bay are doing. Hudson Bay is frozen between November and July each year, and, during this time, Polar bears are far out on the ice in search of food. They feed on seals, walrus, and sometimes even whales; this diet is very high in fat which they store in their bodies. When the ice melts, Polar bears spend four to eight months on shore around Churchill, Manitoba, where they do very little activity and do not spend much time hunting or eating (this is called â€śfastingâ€ť). As a result, the few months they have to hunt seals on the ice are very important because they provide the bears with energy and body fat needed to survive on shore during the summer.
You Are What You Eat!
Climate change is causing Arctic ice to break up and melt several weeks earlier than in the past, meaning the bears have less time on the ice to feed. This habitat change could affect their health and reduce the number of cubs they can raise. To learn how Arctic sea ice loss is affecting the health of Polar bears we look at their stored body fat by taking samples from the rump of every bear we find. Fat is made up of smaller parts called fatty acids. Certain prey species have a unique collection of fatty acids, so from the samples we can tell what the Polar bear has eaten. This method of studying diet is new but very useful because it can tell us the type of seal species Polar bears have been feeding on during the past few months. Since we have fat samples collected from the past 20 years we can determine if Polar bear diets have changed over time, and if this change is linked to the timing of melting Arctic sea ice.
Why Should Scientists Study Polar Bear Diet?
Polar bears need sea ice to survive. Unlike other bear species that can live on shore and eat berries or fish, Polar bears need a diet high in fat and the only way they can get to their prey is by hunting on the sea ice. By studying changes in their diet we hope to find a very important link between climate change, habitat loss, and Polar bear feeding behaviour. We use a place like Churchill, Manitoba because we already have so much information on the same bears year after year which helps us to predict how other Polar bear populations may react to habitat changes. It is important for us to understand what we can do to help Polar bears and the many other species that are affected by climate change! Thereâ€™s still time to save this majestic animal of the North and Bring Back the Wild!
Luana Sciullo is a doctoral student in the Department of Biology at York University where she works with researchers at Environment Canada to investigate long-term shifts in Polar bear foraging ecology and body condition in relation to environmental change in Western Hudson Bay.