Sandesh Kadur / Stump Tailed Macaque (Macaca arctoides) among branches. Gibbon Wildlife Sanctuary, Assam, India.

Sandesh Kadur / Stump Tailed Macaque (Macaca arctoides) female yawning in canopy holding infant. Gibbon Wildlife Sanctuary, Assam, India.

Sandesh Kadur / Northern Pig-tailed Macaque (Macaca leonina) on branch. Gibbon Wildlife Sanctuary, Assam, India.

Sandesh Kadur / Northern pig-tailed macaque (Macaca leonina) sitting on a tree branch. Hoollongapar Gibbon Sanctuary, India. March.

Thomas Marent / Assam Macaque (Macaca assamensis) in threat display, Assam, India

Thomas Marent / Assam Macaque (Macaca assamensis) mother with juvenile, Assam, India

Thomas Marent / Assam Macaque (Macaca assamensis) in threat display, Assam, India

Thomas Marent / Assam Macaque (Macaca assamensis) mother grooming juvenile, Assam, India

Thomas Marent / Assam Macaque (Macaca assamensis) pair in tree, Assam, India

Thomas Marent / Assam Macaque (Macaca assamensis) young, Assam, India

Thomas Marent / Assam Macaque (Macaca assamensis) pair grooming, Assam, India

Bernard Castelein / Assamese macaques ( Macaca assamensis) grooming, Tawang, Arunachal Pradesh, India.