Know Your Primate: Semnopithecus entellus

Order: Primates
Suborder: Haplorrhini
Family: Cercopithecidae
Subfamily: Colobinae
Genus: Semnopithecus (formerly Presbytis)
Species: Semnopithecus entellus
Common Name: Hanuman Langur
The Hanuman langer is spread widely throughout southern Tibet and Nepal, Pakistan, India, Bangladesh and Sri Lanka. They are medium sized to large monkeys getting up to about thirty inches long (not including their long tail) and weighing up to about 50 pounds. They are mainly quadrupedal and highly terrestrial.

They are found in most habitats in the above countries and are somewhat diverse morphologically. The eat fruits, flowers, and new leaves (and whatever cultivated crops they can obtain). They are largely diurnal – although a midday sleep period has been observed. Social groups vary in size from 10-100 individuals and are usually single male groups. Although, as in a number of other primate groups, the groups seem to be centered around related females (aunting behavior is observed). Occasionally, a roving group of males will oust the resident male from his group and take over, whereupon one male then drives the rest of the group off. Infanticide is known to occur in those situations. Interestingly enough, when the habitat is rich and the population is below carrying capacity multimale groups do occur, whereas in environments that experience seasonal stress single male groups occur.