Homogenization of bird communities

Biotic homogenization is characterized as a process by which means species invasions and extinctions increase the genetic, taxonomic or functional similarity among ecological communities and this process is associated with modern biodiversity crisis. The most prominent patterns of recent homogenization of species composition in avian communities are loss of native species and their replacement by non-native species, expanding habitat generalists at the expense of native and more specialized species. As a result, increases in local or alpha-diversity typically occur at the expense of decreased beta-diversity or increased community similarity among regions. These patterns are probably caused by introduction non-native species, urbanization, landscape fragmentation and disturbance. These results suggest that conservation effort should focus on protection of unique habitats where ecologically specialised species occur. Further research in this area could provide better basis for generation of simulation models aimed to predicting changes in community composition