Saturday, September 30, 2017

Northern Plains Langur


The Northern Plains Langur (Semnopithecus entellus) is a species of grey langur found mainly in the central portions of India.  It is one of the most widespread langur species of India and is frequently found living in human settlements.  It is one of the eight grey langur species found in India.

Physical Features
The forward bending tail of a Northern Plains Langur
Northern Plains Langurs can range from greyish-brown to yellowish-brown in colour.  Its ventral side may be buff or pale orange while the face is black in colour.  It lacks a mane unlike the langurs found further north.  The hands of a Northern Plains Langur are very long as an arboreal adaptation and are black till the wrists.  Its fingers are long and slender enabling them to grip on to branches.  The body length of Northern Plains Langurs (excluding the tail) is around 2-2.5 feet for males while females are around 1.5-2 feet long.  It has a forward bending tail like all the grey langur species found in the north which distinguishes it from the southern species of grey langurs, which have backward bending tails.  Their prehensile tails can reach lengths of 3 feet.  Males and females weigh around 10 kilograms.


Distribution and Habitat
Northern Plains Langurs are common in human settlements
The Northern Plains Langur is the most widespread and populous species of grey langur in India.  It is found in the states of Madhya Pradesh, Bihar, parts of Rajasthan, Gujarat, West Bengal, Chhattisgarh, Orissa and Maharashtra.  It has been introduced in parts of Bangladesh.  It ranges from the Godavari river in central India to river Krishna in the south east and river Narmada in the south west.  It is found in a wide variety of habitat; from deciduous forests to scrub land.  It has become very common in human settlements and large populations can be found in various towns.  Some cities like Jodhpur, Rajasthan have populations of several thousand.

Behavior and Reproduction
Langurs grooming each other
The Northern Plains Langur is a social animal and lives in groups that can have up to 100 individuals.  In a group, there may only be a few resident males.Only male groups are also common though they are smaller in size.  Females carry out activities like foraging and grooming.  The females generally groom the males and care for their babies.  Males leave the group once they attain adulthood.  Northern Plains Langurs are diurnal animals and generally prefer high branches while sleeping at night although they have adapted to sleeping on man-made structures.  Females have a gestation period of around 200 days and generally give birth to a single infant.  The infants usually remain attached to the mothers' chest spending most of their time suckling or sleeping for the first two weeks.  Females may also take care of infants that are not theirs.  Infanticide by the males are common especially in groups which are head by a single male.  

Diet
Northern Plains Langurs are mainly herbivores.  They feed on fruits, roots, shoots, bamboos, leaves and shrubs.  They have also adapted to human food and a often fed by people.  Agricultural lands are frequently invaded by these langurs for feeding purposes.

Conservation and Threats
Northern Plains Langurs are rated as Least Concern by the IUCN, indicating that they are not at the risk of extinction.  Indian laws prohibit killing of these langurs.  They are considered sacred by Hindus and are looked upon as 'Hanuman', the monkey god in Hindu mythology.  Since they are not as notorious as the rhesus macaque, they are not considered as pests.  Many langurs are killed every year due to road accidents.  They are also threatened with habitat destruction, forest fires and mining.  Habitat fragmentation has caused them to find shelter in human settlements.