A Wroughton’s free-tailed bat. Picture by Manuel Ruedi

Guwahati, Jan. 9: The discovery of new colonies of Wroughton’s free-tailed bats (Otomops wroughtoni), an extremely rare species in the caves of Meghalaya, has helped double the world’s population of this mammal.

The discovery was reported in the latest issue of Journal of Threatened Taxa following the survey last year by researchers working under the Caving in the Abode of the Clouds Project in collaboration with the Meghalaya Adventurer Association.

“Visual counts indicate that at least 90 bats occupied these new roosts in the caves of Jaintia Hills, which doubles the world’s known population of this species. The new populations of Wroughton’s free-tailed bats have considerable value for the conservation of this elusive species,” said Manuel Ruedi of the department of mammalogy and ornithology, Natural History Museum of Geneva, Switzerland, and one of the co-authors of the paper.

At present, the International Union for Conservation of Nature (IUCN) considers the species under the data-deficient category, as a result of the scarcity of records about their presence.

Meghalaya cave expert Brian D. Kharpran Daly, who is the chairman of the Meghalaya Adventurers Association, said this is an important discovery and would increase the importance of the caves in the state.

“Meghalaya currently has 1,540 caves and more surveys are being done, which will help to discover more,” Brian told The Telegraph.

Cavers have surveyed and mapped around 411km of caves. The bat species is so far known by a single breeding colony in Barapede caves of the Western Ghats, discovered in 1913.

The number of bats present in these caves fluctuates between 40 and 75. Later, two single individuals were recorded in East Khasi Hills of Meghalaya and in Cambodia.

The bat is a powerful flyer and is capable of covering large distances while foraging. Its distinctive external morphology (large size, huge ears, velvet fur) make it easy to recognise and unlikely to be overlooked by previous bat researchers.

Ruedi said the bats were found roosting in three caves near the villages of Pynurkba, Umlatdoh and Thangsah in Jaintia Hills district.

“When we observed and counted the bats in the early afternoon with head lamps, the bats were mostly torpid and reluctant to move to more concealed parts of their roost. None of these bats attempted to take flight, which made them particularly vulnerable to capture,” he said.

Although the gender of the roosting individuals could not be determined, these bats appeared to be adults.

There is concern, too.

“Although Wroughton’s free-tailed bats are classified as strictly protected species under the Indian Wildlife (Protection) Act 1972 (as amended in 2002), the caves in which they roost and the habitats in which they forage in the Jaintia Hills are not,” he said.

He called for a protection plan that would include more extensive surveys and a strict conservation of these caves should be implemented rapidly to mitigate these threats.