New species of Arunachal Macaque named after snow-clad Sela pass

Scientists of the Zoological Survey of India (ZSI) recently identified a new species of Arunachal Macaque and named it after the Sela Pass as it remains geographically separated from other Arunachal macaque of the Tawang district by the snow-clad mountain pass.

The new Macaque species was identified during a field study carried out between 2018 and 2021 in western and central Arunachal Pradesh. The detail phylogenetic analysis of the samples found that it was genetically different from the other species of monkey reported from the region.

Mukesh Thakur, a scientist in ZSI said the Sela macaque is genetically closer to the Arunachal macaque and there are many physical characteristics similar between these two species like a heavy-build shape and long dorsal body hair.

"However, some distinct morphological characters to differentiate them were identified by the team. The Arunachal macaque has a dark face and dark brown coat colour, while the Sela macaque has a pale face and brown coat colour. We also observed distinct behaviours among troops that are common in both species–some troops are habituated to human presence while others avoid human proximity. According to the villagers, the Sela macaque is a major cause of crop loss in the West Kameng district" Thakur said.

"The Sela pass acted as a barrier by restricting the migrations of individuals between these two species for approximately two million years," he said.

The team of experts from ZSI comprised Avijit Ghosh, Mukesh Thakur, Sujeet K. Singh, Ritam Dutta, Lalit K. Sharma, Kailash Chandra and Dhriti Banerjee.

A paper on the study has been published in Molecular Phylogenetics and Evolution, recently.

The paper said Arunachal macaque is reported to have range-restricted distribution with its major populations reported from the high altitude Tawang and West Kameng districts. "Interestingly, the two districts are situated on the geographical proximity but well separated by Sela pass high mountains that remains snow-covered to some extent throughout the year and continued up to Tibetan plateau," it read.

The study was conducted to find out if the high mountain ranges of Sela pass was an obstacle in contiguous movement and gene flow, and spatial concordance of genetic divergence and recognition of taxonomic unit in Arunachal macaque. "Together, findings of these questions will allow us to identify the hitherto undescribed bio-geographic barrier in this region, and open up opportunities to test the consistency of this barrier on specifiction across various taxa," said the paper.