A major goal for the San Diego Zoo and its partners is to understand how polar bears use their senses and perceive the world around them, which will enhance conservation management. This field of study is called Sensory Ecology and takes a multi-prong approach to understanding polar bears.
Acoustic Communication and Human Disturbance
Research projects focused on the acoustic world of the polar bear will help conserve polar bears by allowing us to estimate the impact of industrial noise on denning female bears and their cubs. We have studied the polar bears’ hearing sensitivity (in collaboration with Hubbs-SeaWorld Research Instititute), and have constructed the first ever comprehensive audiogram for any bear species. With this information, we can now say just how sensitive polar bear hearing is across a wide spectrum of frequencies.
We are also embarking on studies of vocal communication between mother and cub while in the den, and a study on how noise from industrial activities and vehicles penetrates the snow and ice of maternal dens on Alaska’s North Slope.
Studying these three aspects of the acoustic world of the polar bear will allow us to better estimate what types of noise might be disturbing, and what might be the impact from the disturbance. This research is made possible with the support of Polar Bears International (PBI).
Learn more in the Conservation Update newsletter featuring Polar Bears.
Polar bears are solitary most of the year, but during the breeding season, males and females need to find each other. Our research is testing whether males and females can identify each other through scents left in their paw prints in the snow.
Our results thus far suggest that males can identify the scent of a breeding female. The male can then use this scent identity and he can choose to follow her tracks, instead of those of a male, a sub-adult, or a female with cubs.
For the polar bear, there is no energy to waste, so knowing what a potential mate smells like is very important to successful reproduction. This research is made possible by the collaboration with USGS and USFWS Alaska, and PBI.
Environmental Contaminants and Hormone Signaling in Polar Bears
Polar bears are the top predator in the Arctic ecosystem and they feed primarily on seals and whales, which are known to accumulate manmade contaminants in their insulating blubber. As a result of feeding on these species, polar bears exhibit some of the highest concentrations of manmade chemicals measured in any wildlife species.
In several instances, researchers have documented a relationship between chemical concentrations and abnormalities in wild polar bears. At the San Diego Zoo’s Institute for Conservation Research, we are developing a system of screening manmade chemicals for their ability to harm polar bears, and doing this without exposing animals to the potentially dangerous chemicals. Our efforts will enable us to identify chemicals that are a threat to polar bear health so that better informed decisions can be made about the release of chemicals into the environment.
At the San Diego Zoo, we have begun using ultrasound technology to determine changes in a polar bears uterus that would indicate implantation and confirm pregnancy. When a female bear becomes pregnant, the development of her cub(s) will also be monitored. How do you get a 1,200-pound polar bear to allow an ultrasound? Our female polar bears are trained to roll over, giving keepers access to their belly. The fur is dampened and plenty of gel applied. The ultrasound wand is bear-proofed with a long PVC cover for the cord, allowing the staff to reach the bears belly safely.