Smithsonian Institution
Smithsonian Libraries: Zoos, a Historical Perspective
An online sample of maps, drawings and photographs of zoos from over 30 states and 40 countries.
Denver Zoo
Denver Zoo: African (Black Footed) Penguin
The Denver Zoo provides an in-depth overview of African (Black-Footed) Penguins highlighting their habitats, range, adaptations, diet, physical characteristics, and more.