Urbanization buffers seasonal change in composition of bird communities: a multi-continental meta-analysis

Aim: Urbanization buffers the seasonality of climate conditions and food availability and, therefore, may cause a seasonal homogenization of animal communities. However, the global effect of urbanization on the seasonal dynamics of animal communities remains unexplored. Our aim was to study the multi-continental relationship between urbanization and the seasonal change in bird composition and explore the influence of climatic factors on the urban-induced reduction of seasonality of bird composition.

Location: Multi-continental

Methods: We performed a literature review and a meta-analysis. The risk ratio effect size (here referred to as urban seasonality index, USI) was used, considering the number of species seen either in the breeding (spring and/or summer) or the non-breeding (autumn and/or winter) season, and the number of species seen during both seasons between urban and less urbanized sites. Low USI values indicated a decrease in the seasonal change in bird composition in ur...