Local and regional effects of pedestrians on forest birds in a fragmented landscape

I assessed the effects of pedestrians on the distribution of forest bird sp ecies in wooded parks in the city of Madrid within and between fragments. W ithin fragments, increasing levels of pedestrians reduced species richness and overall abundance of individuals within circular plots. The abundance o f foraging individuals of four species (Magpies Pica pica, Blackbirds Turdu s merula, Starlings Sturnus unicolor, and Woodpigeon Columba palumbus) dimi nished when pedestrians walked near sampling plots, as well as their breedi ng densities in relation to increasing disturbance levels. Between fragment s, after controlling for fragment size effects, pedestrian rate was negativ ely related to species richness in two breeding seasons. Species turnover w as positively associated to mean pedestrian rate and inter-annual variabili ty in pedestrian rate. At the species level, pedestrian rate negatively aff ected the probabilities of fragment occupation of 16 species beyond the eff ects of fragment size and isolation. Locally, the short-term behavioral res ponses to visitors may reduce the suitability of highly disturbed parks in such a way as to decrease breeding densities and the probabilities of fragm ent occupation and persistence. The effects of human disturbance in fragmen ted landscapes should be incorporated into management decisions as another relevant factor that may reduce habitat quality.