Current and Predicted Distribution of Indian Flying Fox (Pteropus medius Temminck, 1825) in Nepal

The Indian flying fox (Pteropus medius), the largest of four fruit bat species found in Nepal, is endemic to South Asia and has recently been classified as ‘Near Threatened’ on the global conservation status due to growing threats to its survival. This species plays a vital ecological role in pollinating and dispersing seeds of 26 families of flowering plants in Nepal. The majority of the known roosts are located outside protected areas in human dominated landscapes, which are vulnerable to land use changes and climate change, but these impacts have yet to be evaluated. The roosts of P. medius are distributed within elevations of 75 to 1,322 meters above sea level (a.s.l.), spanning the Tarai, Chure, Inner Tarai, and Middle Mountain regions, with records primarily from the central Middle Mountain and no documentation from the eastern and western parts. Based on the occurrence data of 44 roosts, 12 low correlated bioclimatic variables and land-use data (r < 0.75), we ran an ensemble of machine learning algorithms in R using the ‘sdm’ package. Altogether, four variables — including urban land, mean diurnal range, annual mean temperature, and precipitation of the wettest month — emerged as significant predictors. The current potential distribution of the species spans 7,836 km2, approximately 5% of Nepal’s total land area. Based on future climate scenarios SSP 4.5 and SSP 8.5, our projections indicate that the species’ range will significantly expand within elevations of 500–1,500 m a.s.l. in the Inner Tarai and Middle Mountain regions, while contracting in lower elevations below 500 m a.s.l. in the Tarai and Chure regions. Since roosting colonies are mainly located in settlements and farmlands, the study’s findings can help guide regular monitoring and health surveillance of these colonies. Conservation efforts should prioritize the protection of native, broad leaved tall trees and implement systematic roost monitoring to safeguard existing populations.