Top 10 species fighting extinction with the help of zoos – in pictures

Zoos are also helping the blue-crowned laughing thrush, whose population numbers less than 250 mature birds in the wild in China. Trapping for the bird trade is a major cause of the species' recent decline Photograph: Xie Xiao-fang/BIAZA

The mountain chicken frog, from Dominica and Monserrat, faces extinction due to the rapid spread of the chytrid fungus. The disease has devastated amphibian populations around the world Photograph: BIAZA

About 95% of Britain's white-clawed crayfish have vanished from the country as a result of the introduction of American signal crayfish and disease, prompting UK zoos to breed the species for release in safe areas in the wild and raise public awareness of their plight Photograph: Wolfgang Polzer/Alamy

Just 45 Amur leopards remain in the wild, but there are 220 of the critically endangered cat in a global conservation breeding programmes in zoos around the world with a reintroduction scheme currently in the planning stages Photograph: Chris Sargent/Alamy

Potosi pupfish is among the creatures staving off extinction with the help of zoos. It was endemic to Mexico, but is now extinct in the wild – their limited habitat appeared to be the remnants of a large Pleistocene lake. None of this habitat remains Photograph: Heiko Kaerst/ZSL/BIAZA

A pair of partula snails, also known under the general common names, the Polynesian tree snail and Moorean viviparous tree snail. The cause of their extinction in the wild was a misguided attempt at biological pest control Photograph: Dave Clark/ZSL/BIAZA

Verdcourt's polyalthia tree is found in just three places in the Kilombero valley, Tanzania Photograph: Andrew Marshall/BIAZA

Two female blue-eyed black lemur, Madagascar. The male is black, the female a reddish brown colour. Lemurs are the only primate species other than humans that have blue eyes. They are the most endangered primate species in the world, owing to the destruction of their tropical forest habitat Photograph: Frans Lanting/Alamy

Ploughshare tortoise, Madagascar. The principal threats to the species are believed to be fires started to clear land for cattle grazing, and collection for the pet trade Photograph: Kevin Schafer/Corbis

The scimitar-horned oryx is native to north Africa and is extinct in the wild. As with many other species, hunting has been the greatest threat to populations Photograph: ZSSD/Corbis