David Woodfall / European beaver (Castor fiber) rear view in wetlands, in captive breeding programme .Bevis Trust, Carmarthenshire, Wales, UK, May.

Roland Seitre / Grand Cayman Blue Iguana (Cyclura lewisi), adult that has been reintroduced to the wild from captive breeding programme. Endangered species.

Solvin Zankl / Atlantic sturgeon (Acipenser oxyrinchus) at the captive breeding programme in Berlin, Germany,

Alex Mustard / A young Spiny / Longsnouted / Yellow Seahorse (Hippocampus guttulatus), aquarium image. This seahorse is part of a UK seahorse breeding program. Photographed at the SEALIFE quarantine and breeding fac...

Juan Manuel Borrero / Side-necked Terrapin (Podocnemis unifilis) hatchlings in the hand, and ready to be released. Pacaya Samiria National Reserve. Amazon Basin. Loreto. Peru

Ann & Steve Toon / Common dormouse (Muscardinus avellanarius)torpid, in captive breeding programme, UK

Ann & Steve Toon / Roan antelope (Hippotragus equinus) with young offspring, Mlilwane nature reserve breeding programme, Swaziland, Southern Africa

Ann & Steve Toon / Roan antelope (Hippotragus equinus) with young offspring, Mlilwane nature reserve breeding programme, Swaziland, Southern Africa

Heather Angel / Chinese alligator (Alligator sinensis) swimming in Yangtze, streamline with legs pressed against body. Critically endangered species with captive breeding programme in Anhui Province, China. 2009

Heather Angel / Chinese alligator (Alligator sinensis) group from above, heads above water of Yangtze. Critically endangered species, individuals released from captive breeding programme, Anhui Province, China. 2009

Heather Angel / Chinese alligator (Alligator sinensis) with muddy snou in Yangtze. Breeding programme, Anhui Province, China. 2009.

Heather Angel / Chinese white cheeked gibbon (Nomascus leucogenys) female hanging from tree, carrying baby aged two weeks. Parents released into wild from captive breeding programme. Wild Elephant Valley / Xishuangba...