EFFECTS OF PLANTATIONS AND HOME-GARDENS ON TROPICAL FOREST BIRD COMMUNITIES AND MIXED-SPECIES BIRD FLOCKS IN THE SOUTHERN WESTERN GHATS

摘要

Conservation scientists and policy makers are increasingly aware of the role countryside habitats play in supporting tropical fauna in modern landscapes. We studied the value of different land-uses by examining composition of tropical bird communitiesand mixed-species bird flocks in human-altered landscapes of Thattekad and the Anamalai Hills, situated in two different altitudes, in the southern Western Ghats. Sixteen line transects distributed across tropical rainforests, shade plantations of coffee and cardamom, timber monocultures of teak, tea plantations, and home-gardens were surveyed for bird flocks, vegetation structure, foliage profile, and canopy attributes. Results indicate that tea plantations were extremely altered habitats, supportingfew rainforest species and were devoid of mixed-species bird flocks. Teak monocultures had high species density but were less conducive for rainforest species that require a well-developed and structurally more complex habitat. While bird species richness varied little across land-uses, there was significant variation in community composition, with some sensitive bird species absent from all altered habitats. Coffee plantations with surviving rainforest fragments and cardamom plantations with more native shade trees that mimicked a forest habitat supported more rainforest bird species both in communities and flocks. Maintenance of these shade plantations and restoration of forest fragments is recommended, while their conversion into a poor, more open habitat (tea, teak) is strongly discouraged for bird conservation in fragmented landscapes.