CREW Animal Research

Polar Bear – A species threatened with extinction

The polar bear has become an icon for global warming in political and public arenas.  Because sea ice is an essential component of the polar bears’ ecosystem, a change in its distribution and longevity due to global warming could profoundly affect the species’ future.  Because of this impending threat, the species was recently listed as threatened under the U.S. Endangered Species Act.  Zoos are strategically breeding this species in efforts to develop a self-sustaining captive population while employing these charismatic ambassadors to educate visitors about global warming and wildlife conservation.

Predicting Polar Bear Pregnancy

High neonatal mortality and poor overall reproductive success in captive polar bears threaten the genetic health and long-term viability of this species in zoos.  Furthermore, population management by the Species Survival Plan (SSP) is particularly challenging because of the pronounced seasonality of this species and associated timing of breeding and cubbing seasons.  CREW scientists recently discovered a method for noninvasively monitoring the reproductive status of polar bears through fecal hormone analyses.  CREW is now initiating a nationwide project to study polar bears in breeding situations. The results of this project will lead to a better understanding of the species' basic biology, and from a more practical perspective, a method for pregnancy diagnosis in polar bears will, 1) assist the SSP in its population management decisions, 2) facilitate zoos' efforts to manage their bears for reproductive success, and 3) improve the overall welfare of captive bears.

Pretty Polar Bears = Powerful Ambassadors

Visitors often are awestruck by the magnificent polar bears they can observe up close in zoos.  However, some polar bears develop a skin condition and/or lose their hair during certain times of the year.  Although these conditions typically are not a threat to the bear’s overall health, they can adversely affect public admiration.  Many theories for these problems exist including diet, water type (salt vs. fresh), water treatment, season, allergies, etc., but no conclusive cause and effect relationship has been determined.  CREW scientists are currently testing the hypothesis that the condition is related to hormonal imbalances experienced by bears under captive management.  Perhaps the cure will be as easy as a simple hormone supplement.