Habitat heterogeneity influences avian feeding guild composition in urban landscapes: evidence from Bhubaneswar, India

Abstract

BackgroundHabitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features (natural or human-modified) play a crucial role in the avian species composition and population structure. To examine this, a study was carried out in Bhubaneswar, India, to understand the ecological niche distinction in birds based on habitat heterogeneity. Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds. The birds were classified into 11 types of foraging guilds.ResultsThe insectivorous guild had the highest bird species richness (181 species) and the omnivorous guild had the lowest (11 species). The piscivorous guild and wetland habitat had the strongest linkage, followed by the insectivorous guild and agricultural land. The frugivorous guild was significantly correlated with forest habitats (r = 0.386, p < 0.01) and park and garden habitats (r = 0.281, p < 0.01). This urban area hosted a higher number of bird species in certain habitat types, viz., agricultural lands (52%, 115 species) and forest patches (50%, 111 species).ConclusionThe present study highlights the importance of agricultural lands, forest patches, parks and gardens, and wetlands inside the cityscape for supporting avifauna. It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna. Thus, the city development plan must invariably include strategies for conserving the forest patches inside the urban area. Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes, which will help in further reducing the bird population decline in the urban landscape.