Diversity and community structure of wild vertebrates in the Sandwip Island of Bangladesh

Abstract

<p>Islands are one of the fragmented ecosystems that cover an extensive range of microhabitats for diverse wildlife fauna. Biodiversity of this unique ecosystem tends to continuous degradation due to various natural and man-made pressure that primarily necessitates the assessment of the current status of species diversity for taking initiatives to protect the insular fauna. We conducted a survey-based study to assess the vertebrate wildlife diversity in Sandwip Island of Bangladesh in alpha and beta levels including abundance, and distribution pattern. The island harboured a total of 151 species of wildlife, including birds (119 spp.), amphibians (14 spp.), reptiles (13 spp.) and the least abundant mammals (5 spp.). According to the Shannon–Wiener index of the wild vertebrate community, the rural areas contained the highest species diversity (H′=3.79), while the Pielou index indicated that the semi-urban areas had relatively higher (0.876) species evenness. Species turnover signifcantly varied among rural, semi-urban and urban sites (Analysis of Similarity test, R=0.40, P=0.0001). Non-metric multidimensional scaling (NMDS) plot also revealed diferent species compositions between major three sites. The dendrogram of cluster analysis produced larger species clusters for grasslands, agricultural lands and homestead microhabitats. Sixty-seven species showed the highest clumped distribution pattern. This baseline data signifies the rich biodiversity of the island and has implications for prioritizing conservation measures to protect the insular fauna of Bangladesh.</p>