Composition and structure of a snake assemblage in an altered tropical forest-plantation mosaic in Bangladesh

Abstract

Despite the growing trends in quantitative field studies on tropical snake assemblages around the world, Asian tropical snake assemblages have remained less profoundly studied. A snake assemblage in an altered tropical forest-plantation mosaic in Bangladesh was studied for six months. Data were collected on the species composition and their relative frequency of occurrence. On the basis of these data, some major patterns highlighted by earlier studies on tropical snake ecology were tested. More specifically, we tested, the existence of: (1) non-random habitat niche partitioning, (2) the energetic equivalence rule, and (3) different mean body sizes among snake guilds, with distinctly smaller body sizes being expected among the subterranean species. A total of 374 specimens belonging to 34 different species were collected. High mean habitat niche overlap among species was observed, and there was no apparent non-random niche partitioning by snakes either considering all species together or dividing them by guild. The ‘energetic equivalence rule’ was verified, with larger species being less abundant than smaller species. Body sizes differed significantly across species’ habits, with subterranean species being not only significantly smaller but also revealing the least interspecific variation, and terrestrial/arboreal species showing the greatest interspecific variation. Overall, tropical Asian snake assemblages seem to be similar to tropical African snake assemblages in terms of their general organization.