Impact of Environmental and Disturbance Variables on Avian Community Structure along a Gradient of Urbanization in Jamshedpur, India

Gradient pattern analysis was used to investigate the impact of environmental and disturbance variables on species richness, species diversity, abundance and seasonal variation of birds in and around Jamshedpur, which is one of the fastest growing cities of India. It was observed that avian community structure is highly influenced by the vegetation habitat variables, food availability and human-related disturbance variables. A total of 61 species belonging to 33 families were recorded from the suburban area. 55 species belonging to 32 families were observed in nearby wildland habitat consisting of natural vegetation whereas only 26 species belonging to 18 families were observed in urban area. Results indicated that the suburban habitat had more complex bird community structure in terms of higher species richness, higher species diversity and higher evenness in comparison to urban and wildland habitat. Bird species richness and diversity varied across seasons. Maximum species richness and diversity was observed during spring season in all type of habitat. Most of the birds observed in urban areas were found to belong to either rare or irregular category on the basis of their abundance. The observed pattern of avian community structure is due to combined effect of both environmental and human related disturbance variables.