Himalayan Gray Langur 

Syllabus: General Studies Paper 3

Differences in altitude make a primate species in the same Himalayan habitat choose between flowers and fruits as food options beyond their staple menu of leaves, a new study has revealed.

Himalayan Gray Langur

• The Himalayan Gray Langur or the Chamba Sacred Langur ( Semnopithecus ajax) is a colobine, meaning leaf-eating monkey. 
• It is considered an endangered species globally as its population is estimated to be less than 1,500 mature individuals in 15-20 groups.
• The Himalayan Gray Langur was once considered a sub-species of the Semnopithecus entellus, commonly known as the Bengal Sacred Langur or Hanuman Langur, but it was separated as a species in 2005.
• In India, most langurs comes under the genus Semnopithecus.
• Prior to 2001, Semnopithecus entellus (Hanuman Langur) was considered only one species, with several subspecies.
• It was in 2001 that these subspecies were recommended as separate species under the genus Semnopithecus.
• Accordingly, seven different species have been recognised which include Semnopithecus ajax.
• In the Indian Subcontinent, their distribution is reported from Himachal Pradesh, Jammu and Kashmir and from Pakistan and Nepal.
• S ajax is an endangered species according to the International Union for Conservation of Nature Red List but after reassessment in 2004, it was re-designated as ‘Critically Endangered’.
• It is considered endangered due to its restricted range habitat.

Findings

• Three primatologists studied the diet composition of five such groups in and around the Kalatop-Khajjiar Wildlife Sanctuary in Himachal Pradesh between September and November 2020. 
• They especially concentrated on two groups, one inhabiting the Kalatop forest at an average altitude of 2,396 metres, and the other based in the Khajjiar forest at an average altitude of 2,188 metres.
• The domains of the two groups were only 208 metres apart, but the altitudinal gap made a huge difference when the monkeys took a break from feeding on the leaves of some 20 species of plants, primarily the Himalayan ivy ( Hedera nepalensis) and the Himalayan oak ( Quercus oblongata).
• While the Kalatop group satisfied their craving for something different by feeding on flowers. 
• The Khajjiar group ate fruits for a change of taste. 
• Flowers and fruits constituted 11.11% and 15.49% of the diet of the two groups respectively.