Avenue Plantations as Biodiversity Havens: A Case Study of Population Status of the Indian Flying Fox, Pteropus giganteus Brunnich, 1782 and Implications for Its Conservation in the Urban Megacity, Delhi, India

Abstract

This study provides the primary information about the population of Pteropus giganteus, a mega fruit-bat, having a permanent roost in avenue plantations of Delhi, India. These avenue plantations of Lutyens’ Delhi have a variety of tree species which serve as habitats for both roosting and foraging of fruit-eating bats, P. giganteus. These avenue trees comprise of species like Terminalia arjuna, Ficus microcarpa, Syzigium cumini, Polyalthia longifolia and Putranjiva roxburghii. The Indian flying fox (P. giganteus) was observed roosting on nine species of avenue trees in Delhi in the present study, which was undertaken for a period of 3 years from April 2014 to June 2017. In this study period, the peak colony size was observed in May, 2014 (1660 individuals). The flying foxes use 9 species of avenue trees for roosting, where the largest colony size was observed on T. arjuna. This zone is the only roosting location of the Indian flying fox in Delhi, which plays an important role in seed dispersal and pollination. The colony size was largest during the spring-summer months which showed a gradual decrease with the decline in temperature during winters. Although, year round T. arjuna had the maximum number of individuals from the colony whereas Cassia fistula, Delonix regia and Bombax ceiba had the least. The result provides the scope for an uncharismatic species beyond protected area and organismal biology, towards linkages of functional landscapes and urban ecosystem services. With proper monitoring, this area has huge potential to be converted into a ‘Conserved Roosting site’ of P. giganteus.