Relationships of area and noise with the distribution and abundance of songbirds in urban greenspaces

To enhance biodiversity in modern cities, it is important to know which factors limit the distribution and abundance of birds in urban greenspaces. In this paper, I explore if area-sensitive and noise-sensitive songbirds can live in urban greenspaces in the City of Puebla and its conurbation (México). Area-sensitive species can be detected with a higher frequency or abundance in larger patches than smaller ones; I consider that noise-sensitive species can be found with a lower frequency or abundance in noisier sites than quieter ones. Using data from 18 study sites, I modeled the distribution of 13 songbirds, and the abundance of 10, as a function of greenspace area and noise levels. Area affected the distribution of six species and the abundance of three, whereas the distribution of seven and the abundance of three different species were related to noise. So, area-sensitive and noise-sensitive birds can live in urban greenspaces. Contrary to my expectations, the abundance of Passer domesticus and Turdus rufopalliatus were inversely related to greenspace area, whereas the distribution of Sturnus vulgaris and the abundance of P. domesticus increased with background noise levels. My results can help to understand the success of these two exotic species in urban environments in México and other countries. The (mostly negative) effects of measured noise levels on the distribution and abundance of studied species were greater than those of greenspace area; therefore, besides increasing greenspace size, I suggest implementing noise-reducing measures to the benefit of birds (and humans) in greenspaces.