tortoises, Tahiti lorikeets, lion-tailed macaques, mhorr gazelles, gorillas, Przewalski's horses, koalas, burrowing owls, elephants, African wild dogs, ocelots, Tasmanian devils, okapi, raccoons, Southwestern pond turtles, bisons, Pallas's cats, and 145 other endangered species. As a result, they have reintroduced more than 30 endangered species back into the wild, and have conserved habitat at 50 field sites. They also have over 200 conservation scientists working in 35 countries around the world. It employs numerous professional geneticists, cytologists, and veterinarians and maintains a cryopreservation facility for rare sperm and eggs called the frozen zoo. The San Diego Zoo Institute for Conservation Research is the largest zoo-based multidisciplinary research effort in the world. Based at the Arnold and Mabel Beckman Center for Conservation Research adjacent to the San Diego Zoo Safari Park, more than 200 dedicated scientists carry out research vital to the conservation of animals, plants, and habitats, locally and internationally. Zoo Corps Zoo Corps is a volunteer program at the San Diego Zoo that enlists high school students to teach guests at the zoo about the animals they are seeing and their place in the ecosystem. It enrolls students between 13 and 17 years of age. The goals are to promote public education about animals and conservation, and to help the students develop their ability to speak in public. The program runs year round in two sessions, one from May through November and one from January through May. Members of the Zoo Corps are expected to volunteer at least once a month. The program utilizes a series of "Kits", which are set on tables throughout the zoo. The kits contain objects that can be used to explain why an animal is endangered or to shed light on the animal's lifestyle. The four kits are "Backyard Habitats", "Saving Species", "Animal Care", and "Sustainability". Architecture Local architect Louis John Gill designed the original buildings, cages and animal grottos and later in 1926, the Spanish Revival-style research hospital, for which Gill received an Honor Award from the San Diego Chapter of the American Institute of Architects. Gill also designed a bird cage at the zoo in 1937, then the largest bird cage in the world. Awards The San Diego Zoo has received numerous awards for its exhibits, programs, and reproduction and conservation efforts. This list includes only awards given to the Zoo specifically, not to its parent organization; for those, see: San Diego Zoo