Living in the big city: Effects of urban land-use on bird community structure, diversity, and composition

Cities represent an important threat to biodiversity at different scales. Nevertheless, little is known on the processes underlying such effects. In this paper we describe bird diversity, structure, and composition patterns in different urban land-use categories. For this, we surveyed resident bird communities in four representative land-use categories of southwestern Mexico City. Our results show that bird communities vary greatly along the different studied urban land-uses, which represent an urbanization development gradient. Bird communities were highly dominated by few generalist species in areas with commercial components, while showed to have higher evenness values in green areas. Bird species richness decreased and bird abundances increased with urbanization intensity. Also, our results indicate that bird species richness and abundance values are sensible to site-specific habitat characteristics. Although we did not find a clear pattern of taxonomic homogenization related to urbanization, our results show that urbanization development entails the functional homogenization of bird communities. Thus, based on our results, we suggest three urban planning and management activities: (1) regulate land-use change related to urbanization; (2) increase the number of green areas within the city; (3) establish bird monitoring programs to identify focal areas that need management and assist with ecological data for urban planning.