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

Sushant Kumar Verma,Thakur Das Murmu,Judi Hewitt

doi:10.1371/journal.pone.0133383

Abstract

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.

Highlights

Various degrees of human settlement result in differentiation of a landscape in to urban, suburban and rural areas
The maximum species richness was observed in suburban area (61 species from 33 families) followed by wild land area (55 species from 32 families) with urban being taxonomically poorest (26 species from 18 families)
Analysis revealed that suburban habitat had significantly higher species richness and diversity than urban habitat: high Margalef’s index (F = 520.57, P< 0.0001), high Shannon-Wiener diversity index (F = 91.11, P< 0.0001)

Summary

Introduction

Various degrees of human settlement result in differentiation of a landscape in to urban, suburban and rural areas. Lack of appropriate adaptations to utilize available resources is the main reason of species loss from urban environments [23] Such comparative studies on species richness and abundance of birds with various degree of urbanization is lacking in developing nations and needs further investigations in rapidly growing countries like India to study ecological effects of urbanization on avian community. As environmental factors are greatly influenced by weather conditions it is hypothesized that seasonality of bird occurrence may depend on environmental variables which strongly influence species diversity and richness patterns in different habitats along urbanization gradients Such type of study may be useful in identification of most vulnerable species of the studied area [8] as well as useful to conservation planners, urban planners, and land managers

Materials and Methods

Ethics statement

Results

Discussion

United Nations World Urbanization Prospects