Will climate change impact distribution of bats in Nepal Himalayas? A case study of five species

Abstract

Nepal Himalayas combine Oriental and Sino-Japanese zoogeographic realms as well as those of the eastern and western Himalayas. Physiography coupled with the diverse local climates has enriched the biodiversity of the Nepal Himalayas. The order Chiroptera constitutes more than 25% of the mammalian fauna and forms the most speciose group of mammals in Nepal, where bats are recorded within a wide range of elevations from 64m to 4154m. Climate variation in the past has been observed and projected change has been predicted, and an evaluation of the climate change impact on biodiversity and habitats has been initiated. However, none of the studies has assessed the impact of climate change on bats in the Himalayan range including Nepal, despite bats represent the largest mammalian group in the country. Through Species Distribution Modelling (SDM), we describe the present distribution range for five common species, further assess their response to future climatic changes. Specifically, the occurrence of bats against 10 environmental variables were projected under different climate scenarios; present, Representative Concentration Pathways (RCPs) 4.5 and 8.5 for 2050 and 2070 deploying maximum entropy modeling (MaxEnt). We prepared predicted distribution range maps and estimated area using Arc GIS 10.7.1. Among 10 uncorrelated bioclimatic variables, six contribute to the SDM significantly. Annual precipitation (bio12) is the most common variable for all five species. Two species shows wider present distribution ranges compared to other three. Under the climate change scenarios, although predictions varied among species, similar trends of the range shifting toward northern latitudes and higher elevations are observed. Since the larger part of the current potential distribution range lies outside protected areas, a landscape level conservation approach prioritizing bat conservation is needed. Future surveys should target ground truthing in the western region of the country.