The Oregon Zoo hosted a polar bear birthday party in honor of 22-year-old Yugyan and 23-year-olds Conrad and Tasul on December 28.

The birthday bears will receive presents, snow treats and ice cakes made by the zoo's executive chef, Paul Warner.

Zoo visitors were invited to join the party and enjoy cupcakes from Haggen Food and Pharmacy.

"Polar bear birthday parties are fun for the bears and for our visitors," said Tony Vecchio, zoo director. "However, we plan these activities to bring attention to what's happening to polar bears in the wild."

Slideshow: Conrad and Tasul as baby bears

According to Vecchio, the primary threat to polar bears is climate change. The sea ice is arriving later and later in the season and melting sooner, which puts greater stress on the bears.

"We hope we can spark an emotional connection," Vecchio said, "so people care more about the future of polar bears."

As the ice over the Arctic Ocean continues to shrink, the wild polar bears that depend on the sea ice for their survival will suffer. The World Conservation Union's Species Survival Commission has recommended that the polar bear be reclassified as a vulnerable species, and has placed it on its Red List. The Red List identifies species facing a high risk of global extinction.

Conservation groups are also urging legislators to classify polar bears as threatened under the U.S. Endangered Species Act, to further protect the bears from the consequences of global climate change and other threats.