Tim Laman / Tapanuli Orangutan (Pongo tapanuliensis) Beti, juvenile female, daughter of Beta, in the trees, Batang Toru Forest, Sumatran Orangutan Conservation Project, North Sumatran Province, Indonesia

Roland Seitre / Pileated gibbon (Hylobates pileatus) female climbing through trees, Angkor Centre for Conservation of Biodiversity, Siem Reap, Cambodia. Endangered species.

Anup Shah / Sumatran orangutan (Pongo abelii) female 'Juni' aged 12 years swinging from a liana. Gunung Leuser National Park, Sumatra, Indonesia. Rehabilitated and released (or descended from those which were rel...

Anup Shah / Bonobo (Pan paniscus) adolescent male leaping through the trees, Lola Ya Bonobo Sanctuary, Democratic Republic of Congo. October.

Anup Shah / Bonobo (Pan paniscus) young male 'Api' hanging between trees, Lola Ya Bonobo Sanctuary, Democratic Republic of Congo. October.

Kevin Schafer / Western hoolock gibbon (Hoolock hoolock) female with young swinging through tree, Gibbon Wildlife Sanctuary, Assam, India, Endangered species

Tim Laman / Adult male Bornean orangutan (Pongo pygmaeus) in rainforest canopy, Gunung Palung National Park, Borneo, West Kalimantan, Indonesia

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) juvenile hanging from branch, Volcanoes NP, Virunga mountains, Rwanda

Juan Carlos Munoz / Grey gibbon (Hylobates muelleri) swinging from branch in rainforest and using foot to grip plant vine, Mount Kinabalu NP, Sabah, Borneo, Malaysia

Juan Carlos Munoz / Young Orang utan {Pongo pygmaeus} hainging from rainforest tree, Rio Sungae Kinabatangan, Sabah, Borneo, Malaysia

Anup Shah / Juvenile orang utan (Pongo abelii) swinging on liana over water Gunung Leuser NP Sumatra Indonesia

Anup Shah / Juvenile orang utan (Pongo abelii) swinging on liana Gunung Leuser NP Sumatra Indonesia