Oregon Zoo sponsors lecture by polar bear expert

Wildlife biologist Tom Smith will examine impacts of climate change, human activity

Every Arctic autumn, pregnant polar bears excavate a tunnel in the snow to serve as their over-winter maternity ward. When spring arrives, they emerge with cubs and a huge appetite. This remarkable process — called denning — allows vulnerable infant bears to be born into one of the harshest environments on earth. But as climate change transforms the Arctic, mother bears are being forced to adjust where and when they den. Will their maternal strategies adapt fast enough?

Polar bear researcher Tom Smith will examine the ways climate change is altering the rhythm of polar bear parenthood as the Oregon Zoo kicks off its "Evening with the Experts" series Thursday, April 25, at 7 p.m. in the World Forestry Center's Cheatham Hall.

Dr. Smith, an associate professor at Brigham Young University and research wildlife biologist with Polar Bears International, is an authority on den-emergence ecology. His 20-plus years of researching North American bears have revealed that when ice-free periods last longer than normal, polar bears den later. The delay also causes the hungry mothers to emerge earlier, which prematurely exposes cubs to the brutal Arctic winter.

Smith is also investigating how climate change influences where polar bears stake out their maternity wards. Three decades ago, the majority of polar bears denned on top of the frozen sea, close to their prey. Now, the thin and unstable ice is sending most pregnant bears in search of safer dens on land. When the mother and cubs emerge, they must make the arduous return trip to the sea before they can hunt the seals they need to survive.

Currently, Smith is studying how human activities on the North Slope of Alaska affect polar bear mothers and cubs. As industry moves further north, his findings may help set guidelines to prevent disturbing polar bear mothers and cubs.

In addition to Smith's remarks, speakers from the Oregon Zoo will be on hand to talk about building a better future for polar bears. Senior marine like keeper Nicole Nicassio-Hiskey will discuss recent polar bear welfare breakthroughs at the Oregon Zoo and explain how zoo research supports field conservation efforts. The zoo's "Arctic Ambassadors" will recount their experiences in the Canadian Arctic and explain how people can help save polar bears through simple actions.

"Evening with the Experts," presented by the Oregon Zoo, the Oregon Zoo Foundation and Polar Bears International, is suitable for all ages. Admission is $10, or $8 for zoo members and students with valid ID.

Register here.