Avian species richness, human population and protected areas across Italy's regions

Abstract

Fundamental to environmental conservation, the spatial location of biodiversity, people and protected areas has been studied for the species richness of various taxa, including plants, invertebrates and birds. However, few avian studies have analysed these three-way interactions for total versus breeding, and for threatened, human-avoiding and human-adapted species. Correlations between bird species richness, human population size and protected areas were studied across Italy's regions, controlling for variations in area, latitude, main land cover and spatial autocorrelation. Whilst total bird species richness increases with increasing human population size, breeding species richness does not vary with human population size. The number of globally threatened bird species is positively correlated with human population size, but this correlation is not significant when controlling for overall region bird species richness. There is no evidence that the increase in total bird species richness with human population size is owing to species typically found in urban habitats, and the proportion of human-avoiding species increases with human population size. For all groups of species, there is a negative correlation of the number of species with the proportion of protected area, indicating that the conservation of Italy's avifauna should be addressed over the entire landscape, and not just in protected areas.