Mizoram rewrites India’s bat map with two species never recorded before

Guwahati: Scientists exploring the forests of Mizoram have discovered two bat species never before recorded in India, pushing the country’s known bat diversity to at least 138 species and revealing that Northeast India still holds major secrets about its wildlife.

The discoveries—made by researchers from the Zoological Survey of India (ZSI), Shillong, in collaboration with scientists from other Indian institutions and the Hungarian Natural History Museum—have extended the known range of two Southeast Asian bats into South Asia for the first time.

The findings, published in the journal Animal Taxonomy and Ecology, are based on extensive field surveys carried out across Mizoram between 2023 and 2025.

The two newly recorded species are the Indo-Chinese Thick-thumbed Bat (Glischropus bucephalus) and the Indo-Chinese Mouse-eared Bat (Myotis indochinensis).

Until now, the Indo-Chinese Thick-thumbed Bat was known only from Cambodia, Thailand, Vietnam and Myanmar. Its discovery in Chhiahtlang, Serchhip district, extends its known distribution by about 670 kilometres westward from its previously known range in Myanmar.

The second discovery is even more remarkable. The Indo-Chinese Mouse-eared Bat, previously reported only from Vietnam, Laos and southern China, was recorded from Reiek in Mizoram, extending its known range by nearly 1,300 kilometres into India.

The researchers also believe that a recently published genetic sequence from Bangladesh, previously assigned to another bat species, may actually belong to Myotis indochinensis. If confirmed, it would indicate that the species is more widely distributed across South Asia than scientists had realised.

The bats were identified through a combination of morphological examination, DNA analysis and echolocation studies, providing multiple lines of evidence for their identity.

Lead researcher Dr Uttam Saikia said the discoveries underscore how little is still known about the mammalian diversity of Northeast India.

“Northeast India lies at the meeting point of the Indian and Southeast Asian biogeographic regions. Continued exploration is revealing species and distribution patterns that were previously overlooked,” he said.

The findings also address what biologists call the “Wallacean Shortfall”—a major gap in scientific knowledge about where species occur. Filling this gap is considered crucial for biodiversity conservation, particularly in biologically rich but poorly explored landscapes.

Despite accounting for more than 30 per cent of India’s mammal species, bats remain among the country’s least-studied mammals.

The discoveries add to a series of recent breakthroughs by Dr Saikia and his collaborators, including the description of the Himalayan Long-tailed Myotis and the first Indian records of the Golden-haired Tube-nosed Bat and Titania’s Woolly Bat.

Beyond expanding India’s mammal checklist, scientists say the discoveries reinforce the global conservation significance of the forests of Northeast India, which continue to yield species and range extensions that are reshaping the region’s biodiversity map.

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