Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) two youngsters chase each other up a sloping tree. Bandhavgarh National Park, India.

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) youngster in mid-air leaping from a sloping tree trunk to a nearby tree sapling. Bandhavgarh National Park, India. Non-ex.

Mary McDonald / Northern Plains grey Langur (Semnopithecus entellus) baby holding onto mother, Bandhavgarh National Park, Madhya Pradesh, India

Mary McDonald / Hanuman Langur / Northern Plains Grey Langur (Semnopithecus entellus) baby playing with a stick by its mother. Kanha National Park, Madhya Pradesh, India.

Mary McDonald / Hanuman Langur / Northern Plains Grey Langur (Semnopithecus entellus) baby playing with a stick by its mother. Kanha National Park, Madhya Pradesh, India.

Mary McDonald / Hanuman Langur / Northern Plains Grey Langur (Semnopithecus entellus) mother with baby in tree. Kanha National Park, Madhya Pradesh, India.

Mary McDonald / Hanuman Langur / Northern Plains Grey Langur (Semnopithecus entellus) in leafless tree top. Kanha National Park, Madhya Pradesh, India.

Aflo / Northern plains grey langur (Semnopithicus entellus) group resting by trees, Bandhavgarh National Park, India

David Pattyn / Hanuman / Northern Plains Grey Langur (Semnopithecus entellus) family resting in roots of Banyan tree. Ranthabore National Park, India, June.

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) adult female sitting. Bandhavgarh National Park, India.

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus). A youngster prepares to leap from the controversial fence that now surrounds large sections of Bandhavgarh National Park, to a tree branch h...

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) adult bounds across open ground. Bandhavgarh National Park, India.

Andrew Parkinson / Bengal Tiger (Panthera tigris) sub-adult, about 16-19 months old, running through a meadow with a Hanuman langur kill. Endangered. Bandhavgarh National Park, India. Non-ex.

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) adult sitting in light on forest track. Bandhavgarh National Park, India. Non-ex.

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) adult female appears to sit in contemplative mood. Bandhavgarh National Park, India. Non-ex.

Andrew Parkinson / Hanuman / Northern Plains Grey Langur (Presbytis entellus) adult, backlit by evening sunlight, feeding in an open meadow. Bandhavgarh National Park, India. Non-ex.

David Pattyn / Northern Plains gray / Hanuman Langur (Semnopithecus entellus) family resting in Banyan tree whilst playful juvenile is swinging at tail of adult, Ranthambore National Park, Rajasthan, India

David Pattyn / Northern Plains gray / Hanuman Langur (Semnopithecus entellus) three langurs resting in between the roots of a Banyan tree that is growing on steep mountain side, Ranthambore National Park, Rajasthan,...

David Pattyn / Northern Plains grey / Hanuman Langur (Semnopithecus entellus) drinking at a tap for pilgrims at Ranthambore fort, Ranthabore National Park, Rajasthan, India

Mary McDonald / Hanuman Langur / Northern Plains Grey Langur (Semnopithecus entellus) baby sitting with its mother. Kanha National Park, Madhya Pradesh, India.

Michael W. Richards / Hanuman / Northern plains grey langur monkey and young (Semnopithecus entellus) India

Suzi Eszterhas / Hanuman Langur (Semnopithecus entellus) pair grooming, Bandhavgarh National Park, India

Suzi Eszterhas / Hanuman Langur (Semnopithecus entellus), Bandhavgarh National Park, India

Theo Allofs / Hanuman Langur (Semnopithecus entellus) mother with baby in tree, India

Ingo Arndt / Hanuman Langur (Semnopithecus entellus) group on sleeping rock, Jodhpur, India

Ingo Arndt / Hanuman Langur (Semnopithecus entellus) mother and young, Jodhpur, India

Mitsuaki Iwago / Hanuman Langur (Semnopithecus entellus) portrait, India

Patricio Robles Gil / Hanuman Langur (Semnopithecus entellus) pair in a tree, Ranthambore National Park, India

Patricio Robles Gil / Hanuman Langur (Semnopithecus entellus) family group communal grooming, Ranthambore National Park, India

Patricio Robles Gil / Hanuman Langur (Semnopithecus entellus) in tree, Ranthambore National Park, India

Patricio Robles Gil / Hanuman Langur (Semnopithecus entellus) mother nursing her baby, Ranthambore National Park, India

Shin Yoshino / Hanuman Langur (Semnopithecus entellus) family group grooming, India

Bernard Castelein / Northern plains grey / Hanuman langur (Semnopithecus entellus) jumping across river, Corbet NP, India