Conservation Status: IUCN Red List - Vulnerable
Threats to survival: Climate change-driven sea ice loss in the Arctic
Because polar bears rely on the sea ice to access their primary prey species - ringed and bearded seals - sea ice losses have been correlated with declining body condition, reproductive success, and survival. Our multi-disciplinary research program is focused on aspects of polar bear biology important for conservation management. Along with our partners, we strongly believe that a collaborative approach is fundamental to success. Our Recovery Ecology team has led research in the field and in zoos, and we have also participated in research projects led by other agencies and zoos.
Human activities in the Arctic include industrial scale resource extraction, and these activities can overlap both temporally and spatially with one of the most sensitive periods in a polar bears life-cycle: maternal denning. In order to understand how noise disturbance may impact bears in their dens, we have embarked upon an acoustic ecology study. This research includes a comprehensive description of polar bear hearing sensitivity, investigations on levels and impacts of noise transmission from industrial activities in polar bear habitat, and observations of how polar bear cubs and mothers use acoustic communication during denning. In addition, we are working with field biologists to refine our understanding of how polar bears use scent to find appropriate mates in their vast home ranges. We are also identifying vulnerabilities that may be magnified as climate change further fragments and increases the dynamic nature of polar bear habitat.
Lost hunting opportunities as a result of diminishing sea ice means that polar bears may increasingly experience periods of nutritional stress. Exposure to noise and other human activities may also be stressful for polar bears. Cortisol is a hormone that can be indicative of stress, however, it also has other biological functions. For polar bears, cortisol subtleties may vary with the seasons. In order to accurately interpret cortisol and measure stress in wild bears, we are developing an understanding of normal seasonal changes in cortisol using urinalysis data collected from bears housed at the San Diego Zoo.