Budapest Zoo's 18-year-old polar bear, Vitush, plays with a ball in his pool in Budapest, Hungary, Feb. 5, 2009.
Aerial dancers from Project Bandaloop perform a dance as they rappel down the side of Thanksgiving Tower in Dallas, Texas, on Tuesday.
A Siberian tiger looks after her 6 newly born boys on June 1, 2009 in Harbin, Heilongjiang Province of China.
Giant Panda 'Kai Kai' sits in his enclosure at the Giant Panda Forest exhibit at the River Safari, Nov. 28, 2012, in Singapore. Panda populations are threatened by poaching and a loss of habitat, as well as a low birth rate.