Last month I had the pleasure of traveling to Beijing, China, to attend the Society of Conservation Biology’s annual conference. I was excited to have the opportunity to present our research on the hearing sensitivity of the polar bear to this international audience of conservation scientists. And what better place to talk about polar bears and the cascade of impacts that climate change is bringing to these Arctic specialists and their habitat than a city bustling with development and all of its promise and associated problems.
Carbon emissions from this and other cities all over the world are contributing to the crisis in polar bear habitat. Although the long-industrialized United States still produces more greenhouse gases than anywhere else, and so bears a heavy burden as regards reversing climate change, people in the developing world have an opportunity to nip their contribution to climate change in the bud and direct technological developments toward greener energy sources.
It is impossible to talk about polar bear conservation without setting the stage with a discussion of climate change. All other threats to polar bears in the wild are dwarfed in comparison to the threat posed by the loss of sea ice in the Arctic as a result of increased ocean temperatures in the region. The rate of warming in the Arctic is nearly twice that of the worldwide average, and the polar bear is the most visible victim of this asymmetry. Habitat losses, and concomitant changes in the availability of appropriate prey species, pose a catastrophic threat to polar bears.
But all is not lost, and there is still hope for the polar bear. Climate change is something that each and every one of us can fight simply by making “greener” choices in our everyday lives: turn off the light, bike to work, turn down the air-conditioner. Thousands of miles away, a polar bear is thanking you!
While many bear species are generalists by nature, the polar bear, like the giant panda, is completely dependent on a single habitat feature for survival. For the giant panda it is bamboo. For polar bears, it is the sea ice, and this species is entirely dependent upon it for its survival. Although some subpopulations of polar bear come ashore during the summer months or to den in the winter, all polar bears rely on the sea ice during important phases of their life cycle. Probably the most vital resource the sea ice provides is a platform from which to hunt the ice-loving seals that are the mainstay of the polar bear diet. Without access to these seals, polar bears have a very hard time getting adequate nutrition to support successful reproduction and cub rearing.
The research that we are conducting at the San Diego Zoo’s Institute for Conservation Research focuses on illuminating the sensory ecology of the polar bear. Specifically, we have studied the hearing sensitivity of the bears, and we are now embarking on a study of the use of vocal communication between mother and cub while in the den and how noise from petroleum extraction activities penetrate maternal dens excavated in the snow and ice of Alaska’s North Slope. This aspect of the polar bear’s biology, their sensory ecology and use of acoustic communication, is poorly understood. Yet it is necessary information from which to develop estimates of disturbance from industrial activities in polar bear habitat and a line of research that is ideally suited to the zoological setting.
Given the changes in the Arctic habitat, the impacts on polar bear body condition resulting from these changes, and the ever-present pressure to increase industrial activity in the Arctic, we need to understand how a polar bear perceives its environment and what levels of human-made noise would pose a stressful disturbance or disrupt important communication. Sub-optimal nutrition may also work in concert with other threats or disturbances to polar bears or polar bear habitat, creating a “perfect storm” of negative effects, magnifying the negative impact of disturbance.
I found that my audience in Beijing was keenly interested in the complexity of the conservation threat the polar bear faces. This interest was expressed by scientists from all over the world, and ultimately I found that, regardless of where a particular scientist came from, our conversations came to a consistent conclusion: climate change is a global issue, and each and every one of us can contribute to its reversal.
Megan Owen is a conservation program specialist for the San Diego Zoo’s Institute for Conservation Research. Read her previous post, Conserving Ursids: Polar Bears
Watch the San Diego Zoo’s polar bears daily on Polar Cam!