Threatened polar bears fight for survival.

• Author: Owen, Megan
• Position: Life in the Arctic

POLAR BEARS undeniably are charismatic and, due to the conservation crisis unfolding in their Arctic home, these majestic bears have become the poster species for global warming. This is an apt association because no other species so tangibly illustrates climate change-driven habitat loss. Summer sea ice minima has reached historic lows over the past decade and it appears clear that it will continue to recede unless there is a substancial reduction in global warming.

[ILLUSTRATION OMITTED]

Polar bears technically are described as pagophilic--an ice-loving species. A fundamental function of sea ice is that it provides them access to the ringed and bearded seals that are their primary food source. In years when the sea ice melts earlier than normal, prime seal-hunting opportunities are lost and precious pounds of blubber are not gained. Without an adequate store of blubber, females may not have enough energy available to undergo the extended fast associated with den-based pregnancy and cub-rearing.

Concern for polar bears in the wild led to a partnership between the San Diego Zoo's Institute for Conservation Research and Polar Bears International. Over the past six years, PBI has nurtured a successful conservation affiliation founded on a shared belief that zoological institutions are on the front lines of polar bear preservation, and that promoting a community of field- and zoo-based scientists, educators, and animal care specialists will enhance the percentages for polar bear survival. In 2005, we began a collaborative research program investigating the acoustic ecology of the polar bear. Human activities in sensitive denning habitats on the North Slope of Alaska prompted a need to know how well polar bears hear, and how noise from industrial and vehicular activities may impact them: Are some types of noise more problematic than others? How do females behave when faced with noise from outside the den, and how might that change behavior directed towards her cubs, or her ability to get much needed rest and conserve energy? Are the current regulations in place to protect denning polar bears adequate?

[ILLUSTRATION OMITTED]

Ironically, answering these questions requires knowledge of some fundamental aspects of polar bear biology that had not been addressed previously. Detailed investigation of polar bears' acoustic ecology simply is not feasible in the wild. However, bears in zoos--already filling a much-needed role as conservation...