Impact of reproduction on roost selection of the Indian flying fox, Pteropus medius (Temminck, 1825)

Abstract

A thorough knowledge of ecology and behaviour is a clear requirement for proper conservation and management of a species. The Indian flying fox, Pteropus medius (formerly P. giganteus Brünnich, 1782), lives gregariously in large trees and spends a considerable time at day roosts. The roost sites play vital roles in survival, reproduction and population persistence. This study describes changes in roost selection, colony size and behaviours of P. medius during reproductive and non-reproductive seasons in a large colony at Mohanlal Ganj, Lucknow (India). The colony size was significantly lower during the summer non-reproductive season (486.5 ± 121.1 SD) than during the spring (1942 ± 488.8 SD) and monsoon (2367.7 ± 277 SD) reproductive seasons. The number of roost trees utilised and roost site selection differed across the reproductive and non-reproductive seasons. The bats occupied the southern periphery of the sampled garden during the non-reproductive period (summer), whereas they shifted to the central and northern parts of the garden during the reproductive seasons and winter periods. The reproductively active individuals secluded themselves from the reproductively inactive colony members. The selection of secluded roost sites during the reproductive period demonstrates the need for social exclusion, less disturbance, and reduced mate competition. The higher population size during the reproductive period might be due to the immigration of bats, most probably male individuals, facilitating gene flow from nearby populations and thus increasing genetic diversity and species resilience.