Captive breeding -- where endangered animals in zoos or other facilities are encouraged to reproduce, with the aim of releasing the offspring -- has been credited for saving a number species from extinction in the wild. Pictured, a golden lion tamarin at ZSL London Zoo.
Golden lion tamarin – Found only in Brazil, the golden lion tamarin was driven to the brink of extinction by a combination of deforestation and the pet trade. But the breeding efforts of almost 150 zoos have helped numbers recover to more than 3,000 in the wild.
The California condor was almost wiped out in the 1980s by a combination of hunting, accidental poisoning, and the toxic pesticide DDT.
Here a California condor lands in Marble Gorge, east of Grand Canyon National Park, in March 2007.
Famed for its 3-meter wingspan, the condor's fortunes were revived by the breeding efforts of San Diego Zoo, and others, including the The Peregrine Fund.
Related to the common horse, Przewalski's horse is native to central Asia but by the 1960s it was extinct in the wild.
Captive-bred Przewalski's horses have since been released in Mongolia, China and Kazakhstan. These horses live in the Chernobyl Exclusion Zone.