Species diversity of bats (Mammalia: Chiroptera) in Assam, Northeast India

Bats are known to occur all over the world except in the Arctic and Antarctic regions and a few isolated oceanic islands. Bats have been on Earth for more than 50 million years. Currently, there are more than 1,400 species on the globe. They are the second-largest order of mammals and are widely dispersed across six continents. According to the South Asian Chiroptera Conservation Assessment and Management Plan Workshop report, India has 114 species of bats of which 13 species are under the suborder Megachiroptera. The species Latidens salimalii (Salim Ali’s fruit bat) found in Madurai district of Tamil Nadu and Otomops wroughtonii (Wroughton’s free-tailed bat) found in Belgaum of Karnataka are the two only Indian bat species that are listed on Schedule I of the Wildlife (Protection) Act of India, 1972 amended up-to-date. Bats or chiropteran studies at Assam along with other northeast Indian counterparts are very meager and there is no continuous study data from any places of Assam. Besides some detailed studies on the Indian flying fox (Pteropus giganteus giganteus) most of the other studies are based on opportunistic random catches. On the basis of the available research publications of a few bat researchers of Assam, it can become to the conclusion that currently, Assam’s counterpart of Northeast India has about a total of 39 different bat species under 16 genera. Out of those 39 species, five species are recorded as Megachiropteran species (fruit bats) along with 34 numbers of Microchiropteran species. Most of the microchiropteran species are insectivorous in nature with a few being carnivorous. All the recorded species of the Suborder-Megachiroptera were found to be included under a single family called Pteropodidae. However, microchiroptera species recorded from Assam were found to be spread into five different families such as Emballonuridae, Megadermatidae, Rhinolophidae, Hipposideridae, and Vespertilionidae. The highest numbers of species were recorded under the family Vespertilionidae which is commonly known as “Evening bats”. To date, 19 species are recorded under this family followed by Rhinolophidae with six species. The rest of the recorded families shared 2-4 species.