Population Size Determination Using Photographic Estimation for The Conservation of Cave Nectar Bat (Eonycteris spelaea) at Gunung Reng, Kelantan, Malaysia

Abstract

The cave nectar bat, Eonycteris spelaea, is one of the three fruit bats in mainland Southeast Asia that roost in caves, unlike other fruit bats roosting in the forest. This bat species is an important pollinator for many plant species, including economically important crops including durian, petai and jackfruit. Hence, this study was conducted to determine the population size of cave nectar bat (Eonycteris spelaea) at Gunung Reng, Kelantan, Malaysia, since no information was recorded for conservation purposes. We determined the bat population size using the photographic estimation method at the 13 E. spelaea roosts (5 times per roost) found inside Gunung Reng for 20 days (4-30 August 2019). Our bat population size estimate resulted in about 207 to 344 individuals of E. spelaea (F(4,0) = 5.66, p-value < 0.05). This estimate is a relatively modest population size of bats in an isolated limestone karst surrounded by human-dominated habitats. Though Eonycteris spelaea is listed as Least Concern in the IUCN Red List, it is an important bat species ecologically and economically, contributing to the fruit agriculture economy in Jeli, Kelantan. Future studies should incorporate a combination of bat census techniques with long term planning in mind to completely understand the population dynamics of this paramount bat species.