Habitat patch size and tree species richness shape the bird community in urban green spaces of rapidly urbanizing Himalayan foothill region of India

Abstract

Rapid urbanization is emerging as one of the leading threats to the biodiversity globally. But is especially a cause of concern for tropical countries which are urbanizing much faster and with relatively less urban planning than temperate ones. Urban green spaces are established to reduce the negative impacts of urbanization by conserving a large suite of species. Yet our knowledge on the significance of urban green spaces for supporting urban fauna and enhancing species richness is lacking for tropical countries such as India. We examined how landscape and local scale features of urban green spaces influence bird species richness, density, fine-foraging guild richness and composition during breeding and non-breeding season in Dehradun, India. We quantified landscape level variables in the 250 m buffer around 18 urban green spaces. We sampled vegetation and bird community during breeding and non-breeding season through 52 intensive sampling point spread across 18 urban green spaces. Size of the urban green space at landscape level and tree species richness at the local scale emerged as important predictors influencing bird species richness, density and richness of imperilled insectivorous guild across seasons. Urban green spaces within education institutions and offices experiencing less vegetation management supported higher bird species richness and density whereas city parks were species poor. Community composition was affected more strongly by built-up cover and barren area in the landscape matrix and also by tree species richness at the local scale within urban green spaces. City planners should focus on allocating green spaces within urban settings and expand the formal green spaces. Existing green spaces could be improved by augmenting compositional and structural heterogeneity of vegetation as well as conservation of large old native trees.