Echolocation calls of the two endemic leaf-nosed bats (Chiroptera: Yinpterochiroptera: Hipposideridae) of India: Hipposideros hypophyllus Kock & Bhat, 1994 and Hipposideros durgadasi Khajuria, 1970

Record of bats and their echolocation calls from southern Dolakha, central Nepal

With 52 species, bats make up almost a quarter of all the mammal species in Nepal, and yet remains the least understudied group of mammals. Owing to its diverse geography and climate, more species of bats potentially occur in the country, and acoustic surveys could improve the knowledge of their ecology. So, a study was conducted in Sailung and Melung Rural Municipalities of Dolakha district of Nepal, with the objectives of assessing bat species richness and preparing digital records of their echolocation calls. Using mist-netting and roost survey during three periods in 2018 (late March, late May to early June and mid-November), 10 species of bats were recorded: Cynopterus sphinx, Lyroderma lyra, Rhinolophus ferrumequinum, Rhinolophus luctus, Rhinolophus pearsonii, Rhinolophus sinicus, Hipposideros armiger, Myotis formosus, Myotis sp. and Nyctalus noctula. Ten roosts (mostly caves) were located. Echolocation calls of six of these species were documented, including signals of three species described for the first time in Nepal. This study also reports the fifth record of Myotis formosus in Nepal and new locality record of the species after two decades. The echolocation calls documented hereafter may serve as a reference for species identification for non-invasive studies of bats.

Echolocation calls of some bats of Gujarat, India

Bats play an important role by providing ecosystem services including pollination, seed dispersal, forest regeneration and insect pest control and also serve as bio-indicators. In the present study, we present an acoustic guide to the calls of nine species of bats from Gujarat belonging to families Rhinopomatidae (Rhinopoma hardwickii, Rhinopoma microphyllum), Emballonuridae (Taphozous melanopogon, Taphozous longimanus and Taphozous nudiventris), Rhinolophidaea (Rhinolophus lepidus), Hipposideridae (Hipposideros galeritus) and Vespertilionidae (Scotophilus heathii, Pipistrellus ceylonicus). Discriminant function analysis was used to classify the bat calls to the species level using leave-one-out cross validation. Analysis was carried out separately for constant frequency (CF) calls and frequency-modulated (FM) calls. Bats echolocating with CF calls were classified with 100% success, while in the case of FM calls, the calls were classified with 66.7% accuracy. In species-rich communities, care should be taken while using echolocation calls to identify bats producing FM calls. More such call libraries of bats from other parts of India are needed for non-invasive documentation of chiropteran fauna in different biogeographic zones.