Juan Carlos Munoz / Grey gibbon (Hylobates muelleri) hanging from branch in rainforest, Mount Kinabalu NP, Sabah, Borneo, Malaysia

Juan Carlos Munoz / Grey gibbon (Hylobates muelleri) walking along branch, balancing, Mount Kinabalu NP, Sabah, Borneo, Malaysia

Juan Carlos Munoz / Grey gibbon (Hylobates muelleri) hanging from branch in rainforest, Mount Kinabalu NP, Sabah, Borneo, Malaysia

Nick Garbutt / Male Bornean / Grey gibbon (Hylobates muelleri) in rainforest canopy. Danum Valley, Sabah, Borneo, Malaysia

Nick Garbutt / Male Bornean / Grey gibbon (Hylobates muelleri) hanging in rainforest canopy. Danum Valley, Sabah, Borneo, Malaysia

Theo Allofs / M?ller's Bornean Gibbon (Hylobates muelleri) mother and baby hanging in trees, Borneo, Malaysia

Rod Williams / Mueller's / Grey gibbon {Hylobates muerlleri} female with young, captive, from East Borneo

Rod Williams / Mueller's / Grey gibbon {Hylobates muerlleri} female, captive, from East Borneo

Anup Shah / Grey gibbon

Anup Shah / Grey / Muller's bornean gibbon (Hylobates muelleri) wet after rain, captive, Endangered

Anup Shah / Grey gibbon female and juvenile

Thomas Marent / Muller's Bornean Gibbon (Hylobates muelleri) pair jumping, Tabin Wildlife Reserve, Sabah, Borneo, Malaysia