The diversity and nesting preferences of birds along an urban-rural gradient in the Kathmandu Valley, Nepal

Urban areas worldwide are increasing in size at an unprecedented rate, which is influencing local biodiversity. Most studies of urban biodiversity have focused on urban areas in developed countries, while knowledge from developing countries where much current urbanization is occurring is relatively scarce. Thus, in countries like Nepal that are undergoing significant urbanization (two-fold increase in 30 years), our understanding of the processes and impacts on biodiversity are extremely limited. In this study, we examine species richness, abundance, diversity and nesting habitat preferences of birds in Nepal’s capital Kathmandu in comparison to surrounding rural areas. Species richness, abundance and diversity were higher in rural sites than urban sites with a strong positive association with trees, which was much stronger in urban sites. Anthropogenic materials were incorporated into nests, and included plastics, wires and clothing. This behavior was observed primarily at urban sites, as was nesting on artificial substrates like power lines. Rural nesting preferences were positively associated with local vegetation and negatively with distances to buildings. Urban nesting preference were similar, but also increased with increasing distance to roads. Our results suggest that degrading urban green spaces may have severe impacts on urban avian diversity and facilitate colonization of generalist species, such as the House Crow (Corvus splendens), which was the most common species observed at urban sites. Our findings suggest that the planting and maintenance of trees throughout Kathmandu will help conserve current and future bird diversity.