Conservation on Ice
As a scientist, I try to maintain an objective, analytical perspective when thinking about or discussing my study subjects. However, I can’t seem to talk about polar bears without using words like “amazing,” “spectacular,” “incredible,” and just plain “cool.” I saw my first polar bear in the wild as a graduate student in the early 1990s. I will never forget how impressively fast moving and beautiful this young male polar bear was.
It was a very cold and wet day, and the partially frozen Hudson Bay river delta was a challenging hike. As my field partner (now my husband) and I carefully climbed over rocks along the icy shoreline, this polar bear moved gracefully and stealthily behind us. I have to admit it was scary, and the 50 feet between us and the bear was way too close, but I never forgot just how at home that bear looked in that cold and remote Arctic locale. And I couldn’t help but wonder what it would be like to call the Arctic home.
Back then, climate change was something few people talked about. While a few polar bear biologists had begun connecting the dots between climate change trends and the fate of the polar bear, it was not the primary topic of discussion. Now, it is impossible to discuss polar bears without discussing the imminent threat posed to their existance on the Earth by climate change. Climate change has led to dramatic reductions in sea ice.
For the polar bear, this means they have less time to hunt out on the sea ice, and less time to get the fat stores that they need to survive and thrive in the harsh Arctic environment. For pregnant female polar bears, the threat posed by sea ice loss is especially acute because they depend on their fat stores to support them during the 6-7 month fast associated with their pregnancy and maternal denning period.
Coupled with climate change, petroleum extraction activities on Alaska’s North Slope overlap extensively with polar bear maternal denning areas. Wildlife managers have long considered the possibility that these activities may be disruptive to denning polar bears and protective measures have been in place for decades. However, it is difficult to assess just how much the noise associated with these activities disrupts the bears even with these protections. More importantly, with climate changes impacts on polar bears mounting, the need to assess the impacts of noise disturbance on denning bears has intensified because the action of these two factors together may intensify the impact of either factor alone.
In 2006, we launched a collaborative research project with Polar Bears International focusing on the sensory ecology of the polar bear. A central goal of this project was to gain a better understanding of how noisy human activities impacted females while in maternal dens. More to the point, we have been trying to understand how the polar bear perceives its world, and how much they rely on acoustic communication for successful reproduction and cub rearing. To do this, we have been studying what they can hear, how much noise gets into their maternal dens, and how important acoustic communication is between mothers and cubs.
In the course of these efforts, we have learned a lot about their perceptual world, but we still have a long way to go.
Megan Owen is Conservation Program Manager, Applied Animal Ecology, San Diego Zoo Institute for Conservation Research.