Habitat-wise composition and foraging guilds of avian community in a suburban landscape of lower Gangetic plains, West Bengal, India

Abstract

Documentation of avian assemblages in different ecosystems is very important from environmental monitoring perspective. We assessed the species richness and foraging guilds of birds in different habitats of a suburban area in lower Gangetic plains (Bongaon, West Bengal, India) where no such studies have been done so far. Overall, 119 species of birds were recorded during the study period (June 2015 – May 2016) for the entire study area. Maximum species belonged to order Passeriformes (52 species). Based on species richness of birds, the dendrogram revealed two distinct clusters of habitats, one containing perennial wetland, riverine mixed vegetation and seasonal wetland, and the other with residential area and plantation forest. Generalized linear model (GLM) with negative binomial distribution and log-link revealed that species richness of birds significantly varied between different habitats and seasons. Agglomerative Hierarchical Clustering using avian species richness revealed that the habitats associated with water bodies fall under separate cluster and had higher species richness than the cluster containing habitats without water bodies. Maximum bird species was noticed in perennial wetland followed by riverine mixed vegetation, seasonal wetland, residential area and plantation forest. Richness of insectivores was highest in perennial wetland and riverine mixed vegetation, number of carnivorous species was maximum in seasonal wetlands, while omnivores showed the highest richness in residential area and plantation forests. This area supports two near threatened (NT) species namely black-headed ibis (Threskiornis melanocephalus) and Alexandrine parakeet (Psittacula eupatria). Our study is the first effort towards assessment of habitat-wise species richness of birds in this suburban area which supports good number of avifauna. Findings of the present study could serve as an important baseline to assess the impact of urbanization and habitat change on avian species richness in this suburban landscape, and might also be useful in adopting sustainable and bird-friendly management plan for this area.