Photo credits: 1,5 Zoo Berlin; 2 Zoo Vienna; 3 Assiniboine Park Zoo; 4 Chester Zoo; 6 San Francisco Zoo, 7 Chattanooga Zoo; 8 Cleveland Metroparks Zoo; 9-12 Denver Zoo; 13 The Jackson Zoo; 14-18 Tampa's Lowry Park Zoo; 19 Minnesota Zoo.

But wait! There's much more after the fold!