World's largest collection of mammals, birds, and reptiles, located in San Diego, Cal.
, and administered by the Zoological Society of San Diego. The 100-acre (40.5-hectare) zoo, founded in 1916, has some 800 animal species and some 6,500 plant species. The 1,800-acre (729-hectare) San Diego Wild Animal Park opened in 1972 some 32 mi (52 km) northeast, in the San Pasqual Valley; there over 250 species of animals roam through Asian, African, and Australian habitats. A research department, the Center for Reproduction of Endangered Species (1975) has contributed to the zoo's success in managing and breeding endangered species.