Andrew Walmsley / Sumatran orangutan (Pongo abelii) mother and baby Bukit Lawang, North Sumatra.

Jabruson Motion / Conservation workers carrying a sedated Sumatran orangutan (Pongo abelii) towards vehicles and a transport box, part of a relocation programme, Sei Serdang, Prima, Batang Serangan, Langkat, North Suma...

Tim Laman / Tapanuli orangutan (Pongo tapanuliensis) Togus, adult flanged male, Batang Toru Forest. Sumatran Orangutan Conservation Project, North Sumatran Province, Indonesia.

Tim Laman / Tapanuli Orangutan (Pongo tapanuliensis). Togus, adult flanged male Batang Toru Forest Sumatran Orangutan Conservation Project North Sumatran Province Indonesia

Tim Laman / Tapanuli Orangutan (Pongo tapanuliensis). Togus, adult flanged male. Batang Toru Forest, Sumatran Orangutan Conservation Project, North Sumatran Province, Indonesia.

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

Jabruson Motion / Chainsaw operator cutting down African oil palm ( Elaeis guineensis) in a plantation within the Protected Area of the Leuseur Ecosystem, part of a programme of habitat restoration, Tenggulun, Aceh Tam...

Jabruson Motion / Aerial view of rainforest, showing forest clearance and start of erosion gully on hillside, Suaq Balimbing, Kluet Swamps, Sumatra, Indonesia. 2015.

Jabruson Motion / Juvenile male Sumatran orangutan (Pongo abelii) 'Januar' taking banana from keeper, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Juni' feeding, drinking milk from a cup, with male baby 'Januar' aged 18 months, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra,...

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' feeding on ants, with a juvenile wanting to join in, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' feeding on ants with a juvenile, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' feeding on ants, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' feeding on ants, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Jabruson Motion / Female Sumatran orangutan (Pongo abelii) 'Wati' moving through canopy, Bukit Lawang Orangutan Sanctuary, Gunung Leuser National Park, North Sumatra, Indonesia.

Michael Hutchinson / Titan arum (Amorphophallus titanum), in flower, cultivated specimen in botanic garden, native to Sumatra. Kew Gardens, London, UK. 23 April 2016 This species has the largest unbranched flower inflores...

Michael Hutchinson / Titan arum (Amorphophallus titanum), in flower, cultivated specimen in botanic garden, native to Sumatra. Kew Gardens, London, UK. 23 April 2016 This species has the largest unbranched flower inflores...

Cyril Ruoso / Close up of Sumatran rhinoceros (Dicerorhinus sumatrensis) female close up, part of a breeding program, Way Kambas National Park, Sumatra, Indonesia.

Cyril Ruoso / Close up of Sumatran rhinoceros (Dicerorhinus sumatrensis) female feeding, part of a breeding program, Way Kambas National Park, Sumatra, Indonesia.

Cyril Ruoso / Sumatran orangutan (Pongo abelii) baby reaching up to mother's hand, Gunung Leuser National Park, Sumatra, Indonesia.

Cyril Ruoso / Sumatran orangutan (Pongo abelii) female holding hands with baby whilst hanging from liana. Gunung Leuser National Park, Sumatra, Indonesia.

Cyril Ruoso / Assassin bug (Reduviidae) nymph, Way Kambas National Park, Sumatra, Indonesia.

Cyril Ruoso / Fruit of a Dipterocarp tree (Dipterocarpaceae) seed falling to the ground, Way Kambas National Park, Sumatra, Indonesia.

Cyril Ruoso / Fig tree (Ficus sp) in rainforest, Bukit Barisan National Park, Sumatra, Indonesia.

Edwin Giesbers / Sumatran tiger (Panthera tigris sumatrae), captive, native to Sumatra, Indonesia.

Edwin Giesbers / Close-up of an eye of a Sumatran tiger (Panthera tigris sumatrae), captive, native to Sumatra, Indonesia.

Edwin Giesbers / Sumatran tiger (Panthera tigris sumatrae), captive, occurs in Sumatra, Indonesia.

Edwin Giesbers / Sumatran tiger (Panthera tigris sumatrae), captive, native to Sumatra, Indonesia

Edwin Giesbers / Sumatran tiger (Panthera tigris sumatrae), captive, occurs in Sumatra, Indonesia

Anup Shah / Sumatran orangutan (Pongo abelii) female 'Jaki' aged 16 years with baby daughter 'Jodi' aged 2-3 years - portrait. Gunung Leuser National Park, Sumatra, Indonesia. Rehabilitated and released (or desce...

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 / Sumatran orangutan (Pongo abelii) mature male 'Halik' aged 26 years sitting in a forest clearing watched from a tree by female 'Juni' aged 12 years. Gunung Leuser National Park, Sumatra, Indonesia. Re...

Fiona Rogers / Sumatran orangutan (Pongo abelii) female 'Sandra' aged 22 years portrait. Gunung Leuser National Park, Sumatra, Indonesia. Apr 2012. Rehabilitated and released (or descended from those which were rele...

Fiona Rogers / Sumatran orangutan (Pongo abelii) female 'Pesec' aged 28 years portrait. Gunung Leuser National Park, Sumatra, Indonesia. Apr 2012. Rehabilitated and released (or descended from those which were relea...

Fiona Rogers / Sumatran orangutan (Pongo abelii) mature male 'Halik' aged 26 years lying down - portrait. Gunung Leuser National Park, Sumatra, Indonesia. Apr 2012. Rehabilitated and released (or descended from thos...

Edwin Giesbers / Sumatran tiger (Panthera tigris sumatrae) close-up head portrait, captive

Loic Poidevin / Thomas's leaf monkey (Presbytis thomasi) Geunung leuser NP, Sumatra

Konrad Wothe / Orang-Utan (Pongo pygmaeus) lowering itself from a branch head-first into water. Gunung Leuser National Park, Sumatra.

Suzi Eszterhas / Thomas's leaf monkey (Presbytis thomasi) looking down from tree, North Sumatra, Indonesia

Suzi Eszterhas / Sumatran Orangutan (Pongo abelii) female grabbing the hand of her offspring, aged 1.5 years, North Sumatra, Indonesia. Critically Endangered

Suzi Eszterhas / Sumatran Orangutan (Pongo abelii) mother and playful baby aged 9 months, North Sumatra, Indonesia. Critically Endangered *Digitally removed highlight in background

Suzi Eszterhas / Long tailed macaque (Macaca fascicularis) trying to take banana from Sumatran Orangutan (Pongo abelii and young baby, North Sumatra, Indonesia. Critically Endangered

Mark Carwardine / Sumatran rhino (Dicerorhinus sumatrensis) browsing on forest vegetation. Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia

Mark Carwardine / Close up of the eye of a Sumatran rhino (Dicerorhinus sumatrensis) Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia

Mark Carwardine / Head portrait of Sumatran rhino (Dicerorhinus sumatrensis) Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia

Mark Carwardine / Sumatran rhino (Dicerorhinus sumatrensis) walking in forest, from low-angle. Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia

Mark Carwardine / Sumatran rhino (Dicerorhinus sumatrensis) browsing on forest vegetation. Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia

Mark Carwardine / Looking down on Sumatran rhino (Dicerorhinus sumatrensis) walking through stream. Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia