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.

We studied oribatid (Acari: Oribatida) communities in two distinct microhabitats (litter and root) of the bird's nest fern (Asplenium nidus) in an approximately 4-ha area in a subtropical forest, Okinawa, Japan. We collected a total of 15 729 oribatid mites from 37 ferns and examined whether the size and height of the ferns and the distance between ferns affected the structure of the oribatid communities in terms of the species composition, number of individuals, density (individuals per 100 g dry wt of substrate), number of species and species diversity (Simpson's index). Oribatid communities differed significantly in species composition and density between litter and root components and were evenly distributed horizontally throughout the plot. The density of oribatid mites in the litter decreased significantly with increasing height of the ferns, and the species composition and the numbers of individuals and species in the litter were affected by fern size. Our results suggest that the litter and root of bird's nest ferns allowed diverse oribatid communities to become established, and variations in size and height of the ferns may help to maintain or enhance the diversity of oribatid communities in bird's nest ferns in subtropical forests.

Using the species-area correlation I predicted the percentage of endemic Amazonian mammals committed to extinction by 2020 as an outcome of deforestation resulting from the implementation of mega-infrastructure projects in the Brazilian Amazon. Simulations based on optimistic and non-optimistic deforestation scenarios showed a 2-fold and a 3-fold increase, respectively, in Amazonian mammals committed to extinction. The predicted number of threatened species by 2020 was 5–18% of the total number of endemic mammal species, depending on the scenario and equation used. This increase in extinction rates could be catastrophic for ecosystem stability in the Amazon because the loss of functional groups may produce a cascade effect of species extinctions.