Effects of landscape matrix and plantations on birds in tropical rainforest fragments of the Western Ghats, India.

As large nature reserves occupy only a fraction of the earth’s land surface, conservation biologists are critically examining the role of private lands, habitat fragments, and plantations for conservation. This study in a global biodiversity hotspot and endemic bird area, the Western Ghats mountain range of India, examined the effects of connectivity of rainforest fragments with shade-coffee plantations and the influence of habitat structure and floristics on tropical rainforest bird communities. Systematic sampling for habitat and birds was carried out in 13 sites, including six fragments (three relatively isolated and three with canopy continuity with adjoining shade-coffee plantations and forests), six plantations differing in canopy tree species composition (five coffee and one cardamom), and one control site containing a large relatively undisturbed primary rainforest in the Valparai plateau of the Anamalai hills. Around 3300 detections of about 6000 individual birds belonging to 106 species were obtained. The plantations were depauperate in relation to rainforest in rainforest bird species, particularly endemic species, but one site (cardamom plantation) with an entirely native canopy of tall rainforest trees, had species richness and bird abundance values comparable to that of primary rainforest. Plantation and fragment sites that were less isolated (more canopy continuity in surrounding landscape) tended to support greater number of rainforest and lesser number of open-forest bird species and individuals than more isolated sites. Rainforest bird richness and abundance were positively related to the vegetation component representing densities of woody plants, canes, lianas, and bamboos. Bird community composition was however related only to floristic (tree species) composition of sites. The results indicate that the maintenance or restoration of such attributes in plantations and fragments can aid in bird conservation in the region. The potential of rainforest fragments and shade-coffee and cardamom plantations for bird conservation outside wildlife protected areas is emphasised.