Heather Angel / Giant panda (Ailuropoda melanoleuca) sliding down slope on back after losing footing. Panda Breeding Centre, Wolong, Sichuan, China. January 1987.

Gerry Ellis / Western Lowland Gorilla (Gorilla gorilla gorilla) silverback, Limbe Wildlife Centre, Cameroon

Heather Angel / Giant panda (Ailuropoda melanoleuca) portrait, in falling snow. Captive bred, in enclosure, Panda Breeding Centre, Wolong, Sichuan Province, China. February 2008.

Steven David Miller / A Perentie (Varanus giganteus) using its forked tongue to detect smells, Alice Springs Reptile Centre, Northern Territory, Australia, Captive. May.

Tui De Roy / Floreana giant tortoise hybrid descendants (Chelonoidis elephantopus) feeding on flower. These are descendants of the extinct Floreana giant tortoise, but are hybridised with other species. Fausto Lle...

Juergen Freund / Hand-reared Boongary (Dendrolagus lumholtzi) feeding in a kitchen, Atherton Tablelands, Queensland, Australia.

Juergen Freund / Hand-reared Boongary (Dendrolagus lumholtzi) descending from a tree and climbing onto its carer's back, Atherton Tablelands, Queensland, Australia.

David Perpinan / Various Songbirds (Passerine) in cages, confiscated from illegal wildlife trade, Brazil.

David Perpinan / Blue fronted amazon (Amazona aestiva) chicks, confiscated from illegal wildlife trade, Brazil.

David Perpinan / Close-up of a carer feeding a Blue fronted amazon (Amazona aestiva), confiscated from illegal wildlife trade, Brazil.

Andy Rouse / Giant panda (Ailuropoda melanoleuca) cub aged five months falling asleep in a tree in a breeding centre, Chengdu, China. Captive.

Andy Rouse / Giant panda (Ailuropoda melanoleuca) cub aged five months stuck after climbing a tree in a breeding centre, Chengdu, China. Captive.