Macaque selai. Credit: Mukesh Thakur

Zoologists have discovered a new species of macaque which roams the forest of western and central Arunachal Pradesh1.

Genetic analysis revealed that this monkey is genetically different from the other species of monkey found in this region. The researchers have named it ‘Sela macaque’ (Macaque selai) after the Sela mountain pass, which geographically separates this species from its close cousin -- the Arunachal macaque -- found in Tawang district.

The researchers say the pass acted as a barrier by restricting the migration and mixing of these two species for nearly two million years.

Scientists at the Zoological Survey of India in Kolkata collected a few DNA samples from the new macaque species and carried out detailed phylogenetic analysis.

The researchers, led by Mukesh Thakur, found that the Sela macaque is genetically closer to the Arunachal macaque and members of these two species share some physical characteristics like a heavy-built shape and long dorsal body hair.

However, the individuals of the two species acquired some distinct morphological features when they evolved separately. The Arunachal macaque has a dark face and dark brown coat colour, while the Sela macaque has a pale face and brown coat colour.

The researchers also observed that some troops of monkeys are used to human presence while others avoid humans. The Sela macaque, villagers reported to them, also destroys crops in the West Kameng district of Arunachal Pradesh.

The researchers say these findings may help devise conservation efforts and management of the Arunachal macaque.