Spatial patterns of species richness and distribution in breeding land birds of the Central Indian Highlands.

Abstract

Variations in number and distribution of species in space constitute one of the fundamental themes in ecological research. It is being increasingly recognized that studies on species diversity at regional scale are essential to understand the mechanisms of maintenance of biological diversity. Emergence of macroecology, where large-scale ecological phenomena are examined to test biogeographical hypotheses, has considerably widened the scope of these approaches to include application of empirical patterns in finding solutions to conservation issues. This study, adopting this acroecological framework, investigates the spatial patterns in species richness and distribution of breeding land birds in central India. 2. The study was conducted across the Satpura and Vindhya Ranges, collectively known as Central Indian Highlands, in Madhya Pradesh, India between March, 2002 and September, 2005. Bird species composition is found to be primarily determined by vegetation structure at regional level and by floristic composition at local scale. This finding is consistent with earlier observations that birds respond, in their species composition, to vegetation structure across habitats and to vegetation composition within habitats. The species-area relationship in central Indian birds is best described by power function curve with a slope of 0.12. The acutely low slope points to the extremely sparse nature of spatial gradient in bird species diversity of Central Indian Highlands. The findings of the study clearly illustrate the bias in PA network that a single-species approach can potentially bring about. The recent rediscovery of the critically endangered Forest Owlet (Heteroglaux blewitti), after a gap of 113 years, from these low-rainfall dry deciduous forests highlights the importance of extending adequate protection to all major biomes and the need for multi-species approach in design and maintenance of an efficient PA network.