Recent assessment of the status of the world's vertebrates, using the IUCN Red List, shows an increase of species being classified as 'Threatened'. Without species conservation efforts this rate of deterioration would have been one-fifth higher.
There are 34 animal species classified as Extinct in the Wild on the IUCN Red List of Threatened Species, meaning that these species are known only to survive in human care. Prominent examples of species classified as Extinct in the Wild include the scimitar-horned oryx (Oryx dammah), Père David's deer (Elaphurus davidianus) and Socorro dove (Zenaida graysoni). 85% of species classified as Extinct in the Wild are actively bred in zoos, aquariums and other animal propagation facilities.
The recent evaluation of the impact of conservation on the status of the world's vertebrates, published in the journal Science, showed that conservation breeding in zoos and aquariums played a role in the recovery of 28% of the 68 species whose threat status was reduced according to the IUCN Red List. In this evaluation, species previously classified as "Extinct in the Wild" that have improved in status to "Critically Endangered" or "Endangered" thanks to the reintroduction of captive-bred animals include the Przewalski's horse (Equus ferus przewalskii), black-footed ferret (Mustela nigripes) and California condor (Gymnogyps californianus).
Nevertheless, on average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. So, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species. (Sources: website WAZA; Science, 10.12.2010)
