Sofia Zoo marmoset, and macaques. The predator sector houses big cats, bears and small predators, including lions, tigers, leopards, pumas and brown bears. In January 2011 the zoo received eight Humboldt penguins on loan from Germany. The penguins are on loan for about 18 months, after which they will be returned, with any offspring to stay at the zoo. The zoo has some 1,400 individual birds representing 192 species. Waterbirds are housed in a lake, and Imperial eagles, Griffon vultures, Egyptian vultures and buzzards in a large walk-through aviary. Other species of birds at the zoo include ostriches, Silver pheasants, peacocks, flamingos,
Beijing Zoo collection. Leading Chinese universities also established a research presence in the zoo to study animal behavior and to breed endangered species. The zoo's development came to an abrupt halt during the Cultural Revolution as zoo staff were purged, research work stopped, and contacts with foreign zoos were severed. In the 1970s, as China forged diplomatic relations with the Western bloc, the zoo received animal gifts from the Australia, France, Mexico, Nepal, Spain, Sri Lanka, the United Kingdom, and the United States. The zoo also organized a four-year mission to Ethiopia, Kenya, and Tanzania, which brought back 157 species and 1,000