Use of tree cavities by Indian vertebrates: status of research, knowledge gaps and future conservation perspectives

Tree cavities play a key role in the structure and functioning of forest ecosystems. Though they host rich and specialized assemblages of numerous vertebrate and invertebrate species, they have received limited research attention in India as well as in tropics. We collated information on cavity using vertebrates of India from the available literature and various databases. Overall, 254 relevant references were found with information about tree and/or cavity characteristics and use for 517 species, which is about 18.4% of terrestrial vertebrate species of India. Among the 517 species, 43.9% were birds, followed by reptiles (30.8%), mammals (17.6%) and amphibians (7.7%), and the majority of them are rare, elusive and nocturnal species restricted to different regions/habitats. About 80% of the species are secondary users. Majority of the species use tree cavities as breeding sites (32.7%), and another 7.4% use them as roost, den or hibernation sites. Our analysis also shows that vertebrates use cavities with various characteristics in a wide variety of tree species. We have identified important gaps in research on cavity using vertebrates and cavity-trees. We have also emphasized the need for highly focused long-term studies on habitat interactions to elucidate species level requirements to plan habitat management strategies for the conservation of cavity using vertebrates and their cavity-trees