SAN DIEGO ZOOLOGICAL GARDEN

the largest collection of mammals, birds, and reptiles in the world. This municipal zoo, located in San Diego, Calif., U.S., was founded in 1916 and is administered by the Zoological Society of San Diego. It occupies a 40.5-hectare (100-acre) site in Balboa Park amid hills and canyons. The zoo has about 3,500 animals representing more than 700 species. A noteworthy feature of the zoo is its landscaping. More than 2,500 species of exotic plants are maintained on the grounds, adding atmosphere and frequently providing an element of the natural diet for various animal species. The zoo is famous for its breeding colony of koalas, the only one outside of Australia. The koalas thrive largely because their sole food, eucalyptus, grows abundantly on the zoo grounds. The zoo also maintains successful breeding groups of bonobos (pygmy chimpanzees), Galapagos tortoises, okapis, and bongo antelopes. It has many interesting exhibits, including a large bald eagle flight aviary and a walk-through tropical rain forest. In addition, the zoo serves as a repository for the studbooks of the orangutan and the Arabian oryx. In 1972 the San Diego Zoological Society opened the San Diego Wild Animal Park as a complement to the San Diego Zoo. The park is situated on 728 hectares (1,800 acres) in the San Pasqual Valley northeast of the city. Numerous species of animals roam the park's extensive grounds, and an 8-kilometre (5-mile) monorail system enables visitors to view the various habitat groups, which include those of Asia, East and South Africa, and Australia. Among the animal species that are exhibited in the park are the endangered Arabian oryx, addax, and Eld's deer, as well as the largest captive herd of white rhinoceroses that exists outside of South Africa.