Animals at the Zoo (51 images)

Two polar bears at the San Diego Zoo wrestle and play as they get to know one another in San Diego on June 29, 2007. Kalluk (left), a sub-adult male is being slowly introduced to adult female Chinook (right). Zoo keepers are hopeful that the pair will develop a positive relationship and may become potential breeding partners in the future. Polar bears are a threatened species. (UPI Photo/Ken Bohn/San Diego Zoo)... .

Koyama, a young mountain lion cub, gets accustomed to her new home at the San Diego Zoo on February 20, 2007. Koyama was rescued by the Washington State Fish and Wildlife Service in October 2006, after being found alone in the wild and was estimated to be only two weeks of age at the time. Arriving at the Zoo on November 14, 2006 she went through health appraisals and a quarantine period before going to her home in Cat Canyon. This is the first time in decades that the San Diego Zoo has exhibited mountain lions. (UPI Photo/Ken Bohn/San Diego Zoo)

A lesser spot-nosed guenon holds her newborn baby at the San Diego Zoo on July 6, 2006. The baby, born mid-May, has recently become more visible to Zoo guests as it learns to climb and play. This birth is historical for the world-famous Zoo as it's the first birth of this rare primate species in the Zoo's history. It is also the first birth in the Zoo's newest multi-million-dollar exhibit Joan B. Kroc's Monkey Trails and Forest Tales habitat. The baby has not been named as the gender has yet to be determined. (UPI Photo/Ken Bohn/Zoological Society of San Diego)

Baby panda Zhen Zhen reaches for some leaves at the San Diego Zoo's panda research station on March 21, 2008. The 26 pound panda cub just moved into a new area at the Zoo where she is enjoying exploring and climbing trees. (UPI Photo/Ken Bohn/San Diego Zoo)