The Alaska Zoo hosted one of the world's foremost authorities on polar bears at its annual summer gala and fundraiser Thursday night.

Dr. Steven Amstrup is a 2012 recipient of the prestigious Indianapolis Prize for his conservation efforts. It is awarded every other year to an individual who's made "extraordinary contributions to conservation efforts involving a single animal species or multiple species."

Amstrup worked as a lead researcher for the U.S. Geological Survey in Alaska early in his career, and solved the mystery of where polar bears give birth to their young. In 2007, Amstrup led an expedition to assess future impacts of global warming on polar bears; the nine reports produced by researchers became the basis for the 2008 listing of polar bears as a threatened species under the Endangered Species Act. Polar bears are the first, and so far only, species to be placed on the list due to the threat posed by global climate change.

At the Alaska Zoo event, Amstrup talked about the importance of polar bears at zoos to raise awareness of the animal's struggle in the warming Arctic. Amstrup wasn't the only big draw. Silent and live auctions were held and guests got to visit with many of the zoo's animals. A gourmet dinner also was prepared by Chef Al Levinsohn from Kincaid Grill.