A Gray Langur photographed in Trincomalee, Sri Lanka
The Gray Langur, or the Hanuman Langur, is the most widespread Langur in South Asia. The name "Hanuman" is derived from the Hindu monkey god from the epic Ramayana. This species is widely distributed in Sri Lanka and can even be found in Colombo. A troupe of these monkeys frequents our garden throughout the year. Although the name "Hanuman Langur" is widely used in India to refer to the group as a singe species, seven species of the Gray Langur have been identified. Of these, the Tufted Langur Semnopithecus priam can be found in Sri Lanka. More images and info inside.
A Gray Langur photographed in Anuradhapura Sri Lanka
The diet of the Gray Langur consists of leaves, fruits and flowers. The diet is also seasonal with large leaves being eaten in the winter months and fruit. Insects, tree bark and gum are used to supplement the diet.
Although these monkeys sleep in trees, they spend a considerable amount of time on the ground. They are most active during the day and can often be seen walking on all fours. They live in medium to large groups which usually have a dominant male. Adolescent males who have been expelled from the group form their own bachelor packs. These packs are known to attack the packs that expelled them, with the aim of challenging the alpha males leadership. If they are able to kill the alpha male, a power struggle will ensue and all the infants fathered by the alpha male will be killed.
In India, a relationship seems to have developed between the Chital and troops of the Northern Plains Gray Langurs (another subspecies). The Chital seem to benefit from the Langur's keen eyesight and the ability to have a look out in the tree tops. The look out raises an alarm when a predator is observed in the vicinity. The Langurs benefit form the chitals superior sense of smell to warn them of predators when they are feeding on the ground.