Birds on urban wastelands

Abstract

Responses of birds to urbanisation are manifold. Urbanisation directly influences birds by changing ecosystem processes, habitat and food supply; urbanisation indirectly influences birds by affecting their predators, competitors or disease organisms. A special urban habitat is wasteland since it occurs only for short periods in urban agglomerations. Their habitat characteristics could rarely be found in other urban land-use types. In earlier times, large herbivores, fire, floods, windfall, shifting dunes or dynamics of natural river courses removed vegetation and created open landscapes. In human-dominated landscapes, these processes are mostly prevented. In urban settings, building work, demolition and removal of industrial or railroad areas simulate ecological processes that became rare in human-dominated industrial landscapes. Whereas the population dynamics of open-land species in agricultural areas were intensively studied, urban wastelands were rarely examined. These 'unintentional' habitats are populated by a number of rare species. Thereby, species differ considerably from each other with regard to their requirements. Some bird species are sensible to human intrusion, some avoid densely built areas, and some are sensitive to the surroundings of habitat patches that are irrelevant for others. Most bird species that prosper in urban habitats are generalists, but also some habitat specialists are under certain conditions able to exploit the resources of an urban environment. The aim of this chapter is to show the state of knowledge on birds on urban wastelands, their value as habitat for endangered bird species and the influence of the urban space that surrounds wastelands on their avifauna.