Butterfly Diversity in Relation to Human-Impact Gradient in Outskirts of Kolkata, West Bengal, India

Abstract

Anthropogenic activities may affect species diversity and community structure. Butterfly species diversity in relation to human-impact gradient was evaluated in the Baruipur subdivision, outskirts of Kolkata metropolis, West Bengal, India as a model geographic area. Four study sites situated in bird sanctuaries, rural, suburban and urban areas with different levels of anthropogenic disturbances were selected to assess the human impact on butterfly diversity. A total of 80 butterfly species were recorded during the entire study period with the sanctuary (with minimal anthropogenic disturbance) showing the highest species richness (73) followed by rural (62), suburban (54) and urban (36) study sites indicating a strong negative impact of anthropogenic disturbance on butterfly species diversity. Butterfly species diversity varied significantly among different habitats (p ˂ 0.001). The relative abundance of butterflies also varied seasonally. It is apparent that the area under the present study is able to sustain diverse butterfly species provided natural habitats are protected from anthropogenic disturbances and steps are taken to increase urban greenery to support butterfly diversity and consequent ecosystem services.