Large-scale variations of raptor communities in urban green spaces of neotropical cities

Abstract

Urban areas are expanding continuously inducing changes in raptor communities. However, our knowledge about urbanization impacts on raptor communities at continental scales is scarce. Therefore, the aim of this study is to relate geographical (city location) and environmental characteristics of cities with raptor species richness, taxonomic composition and functional composition in urban green spaces (UGS) of Neotropical cities. Data about raptor species present in UGS was compiled through search of scientific articles and thesis in databases. Raptor species richness increased in the tropics and decreased with increasing altitude. Species richness also increased with the increasing minimum UGS size of studies. Species composition dissimilarity was influenced by altitude and the geographic location of cities, and was dominated by species turnover. Scavengers were more frequent in cities of the east coast of Brazil, whereas semi-open habitat species were more frequent in southern South American cities. Raptor body size was related positively with UGS size. The results obtained confirmed the pattern of increasing raptor species richness in the tropics. However, anthropogenic factors such as green area loss in urban areas may influence the macrogeographical patterns of raptor species richness. The species composition dissimilarity between cities is dominated by a pattern of species replacements, related to species distributions in the Neotropics. Species functional traits were affected by macrogeographical factors and also by green area size, suggesting that urbanization may alter ecosystem processes provided by raptors. In short, the conservation and planning of large UGS is fundamental to maintain raptor communities in the Neotropical cities.