In 1910 San Pedro Park in San Antonio housed a private collection of small animals. In 1914 George W. Brackenridge donated a few elk and buffalo for public display in Brackenridge Park. In 1928 the San Antonio Zoological Society, a nonprofit organization, was established to purchase animals to be housed adjoining Brackenridge and Koehler parks on a fifty-acre tract of land from a Spanish grant that belonged to the city. The site had been a rock quarry, and the resultant limestone cliffs provided a "natural" habitat for the animals. The San Antonio River flowed through the area, and an extensive canal system was developed using its water. The zoo opened in 1929 with 344 specimens in the collection, including seventy-two white-tailed deer and sixty-seven ring-necked doves. The collection now comprises more than 3,000 animals representing more than 700 species. The society oversees building, maintenance, and purchases of the animals; the city provides the land and continues support. The San Antonio Zoo is the only one in the world that exhibits the endangered whooping crane, the giant armadillo, and the shoebill. The first white rhino born in the New World was born in the zoo in 1972. Many endangered species are exhibited and propagated at the zoo, including golden lion tamarins, black rhinos, Grevy's zebras, scimitar-horned oryx, and sable antelope. The zoo features an innovative children's zoo, in which a boat ride passes by islands representing different parts of the world and exhibiting animals native to each region, and an education center where programs are offered for visitors of all ages.