School of Biology, University of Leeds, Leeds LS2 9JT, UNITED KINGDOM.
The Western Ghats of India are a globally important biodiversity hotspot, but around 90 % of the land has been converted to agriculture. Little is known about how bats respond to the conversion of native rainforest to different plantation types in the Western Ghats. This thesis examines the response of bats to coffee and tea plantations, and to riparian habitats, in the southern Western Ghats.
Most bat assemblages in the tropics have been studied by catching bats, but many studies have shown that catching alone can give biased and incomplete results. In order to use acoustic data as well as catching data in this landscape I made a library of the echolocation calls of fifteen echo-locating species in the landscape. Comparisons of the data from each method showed that combining catching and acoustic data gave the most complete picture of the assemblage, but that acoustic data alone detected more species than catching data alone.
Acoustic and catching data were used to build habitat suitability models for ten species. Scales of 100 m – 500 m were the most important for predicting bat presence. Several species showed a positive response to habitats containing native trees and habitat richness, and a negative response to tea plantations and distance to water.
Coffee plantations did not differ significantly from forest fragments in terms of bat species or abundance, but did differ in species composition. Bat assemblages in coffee plantations were functionally very similar to those in forest fragments. Tea plantations had the lowest bat species richness of all habitats and differed in species composition from all other habitats. Bat assemblages in tea plantations had lower functional richness and specialisation than other habitats, and the bats remaining were open-adapted species.
Rivers with riparian corridors did not have significantly greater bat species richness than rivers without corridors, but differed functionally in several ways. Rivers without riparian corridors had reduced functional specialisation and functional divergence. Rivers with riparian corridors supported more forest adapted species than rivers without riparian corridors.