Socioecology of Hanuman langurs: The story of their success

The story of the monkey god Hanuman (Fig. 1) is a story of success, forever captured in the Indian national epic Ramayana. Hanuman was the strenuous and resourceful general of an army of monkeys serving Lord Rama in rescuing his wife Sita from imprisonment at Sri Lanka. With a single leap, Hanuman jumped from the coast of India to the island of Sri Lanka to spy on the situation. By setting the whole town on fire he distracted the guards and, together with his monkey army, later helped to rescue Sita. Many pious Hindus regard the black ("burnt") skin of the Hanuman langurs (Semnopithecus entellus, also known as Presbytis entellus) as proof that they are the living descendants of the monkey god Hanuman (Fig. 2). Moreover, the story of Hanuman langurs also is a story of success. We aim to summarize the current knowledge of the socioecology of Hanuman langurs, referring particularly to new data from our study site of Ramnagar in southern Nepal (Box 1), and to pinpoint promising directions for future research.