Animals at the Zoo (51 images)

Su Lin, a 2-year-old giant panda at the San Diego Zoo, enjoyed the cool feel of snow on an unusually hot day in San Diego on April 27, 2008. The San Diego Zoo's Giant Panda Research Station was covered in 15 tons of snow on Sunday. In two weeks, on May 10, the Zoo's polar bear exhibit will be blanketed with snow as part of Bear Awareness Days, presented by Mission Federal Credit Union. The fun and educational four-day event discusses bear conservation efforts. (UPI Photo/Ken Bohn/San Diego Zoo)

Four-month-old Nyack (R) greets his cousin Ingozi at the San Diego Zoo's Wild Animal Park in San Diego on April 18, 2008. The male lion is now living at Lion Camp after spending the first few months of his life at the Wild Animal Park's nursery where he was hand raised. The male cub was born Dec. 6 following a difficult delivery. While his mother initially tended to the cub, her maternal care began to wane, compromising his health. The cub has since recovered fully and is being introduced to other cubs at Lion Camp. Although his new companions are being raised by their mothers, the cubs spend the mornings away from their parents to help socialize Nyack. (UPI Photo/Ken Bohn/San Diego Zoo)

Trumpeter swans swim with their newly hatched cygnets at Lincoln Park Zoo in Chicago on June 1, 2008. Trumpeter swans were hunted to near extinction by 1900 and now, thanks to managed breeding and recovery efforts, these swans are thriving again in many parts of the Midwest. (UPI Photo/Brian Kersey)

After living in its mother's pouch for more than three months, an endangered brush-tailed bettong joey at Lincoln Park Zoo in Chicago finally emerged on June 5, 2008 . This tiny marsupial which only weighs 2 or 3 pounds when fully grown is native to Southwestern Australia. This rare species was nearly extinct in the wild by the early 1900s due to predation by introduced animals like cats, rats and foxes. Fortunately, managed breeding programs and recovery efforts are underway to ensure species survival. (UPI Photo/Greg Neise/Lincoln Park Zoo)