Neotropical puzzles: Assessing the role of spatial arrangement and human-induced disturbances on the avian diversity of local patches.

Melissa Ardila-Villamizar, Daniel Sánchez, Laurence H. De Clippele, Davide Michelangelo Dominoni

Urbanization expansion poses significant challenges to biodiversity. Studies of urban ecology in the Global North abound, but there is an urgent to understand the drivers of biodiversity decline in highly diverse, yet vulnerable and understudied ecosystems such as Neotropical cities. Specifically, while the influence of environmental, anthropogenic, and ecological factors on biodiversity is well documented, empirical evidence on how specific urban design features such as the spatial arrangement of patches and sources anthropogenic disturbance contribute to these patterns remains limited. Here, we conducted visual surveys (i.e., point counts) across five cities in the Colombian Andes to assess how the spatial arrangement of urban features relative to vegetation, urban infrastructure and human disturbances such as pedestrian and pet density influenced avian diversity. Patches located closer to vegetation, with lower pedestrian density and higher pet density, supported greater species richness and abundance. Interestingly, evolutionary distinctiveness was not affected by the ecological variables considered, whereas functional diversity was highest in patches near urban infrastructure with elevated pedestrian density. Overall, our findings highlight the importance of (1) preserving larger green areas with lower human disturbance to maintain biodiversity within urban ecosystems, (2) habitat edges to promote functional diversity in urban ecosystems and (3) incorporating taxonomic, phylogenetic, and functional dimensions when assessing ecological dynamics. Thus, this study contributes to the understanding of urban biodiversity patterns in an understudied region by identifying key landscape features that support diverse avian communities, offering insights for biodiversity-informed urban planning in rapidly expanding tropical cities.