Population Densities of Birds Breeding in Urbanized Habitats in the Grabiszyn District in the City of Wrocław

Studies were carried out in 2010 by mean of simplified version of the mapping method. The study area (395 ha) was located close to the city centre. It comprised a mosaic of urbanized habitats, with a clear dominance of green areas, such as parks (41.1 ha), gardens, cemeteries and tree clumps. A total of 48 breeding bird species were recorded in the whole study area. The most common (<25 pairs/100 ha) were Passer domesticus, Passer montanus, Sturnus vulgaris, Parus caeruleus, Parus major, Apus apus and Columba livia. Numerous (7-15 pairs/100 ha) were also the following species: Columba palumbus, Turdus pilaris, Sylvia atricapilla, Serinus serinus, Turdus merula and Pica pica. Insectivorous birds were the most common birds constituting 63.3%, and granivorous -32.6% of all pairs recorded. Most birds nested in tree holes (39.3%), in/on buildings (30.2%) and in trees/shrubs (25.6%). Distribution of breeding pairs of 23 bird species was presented on maps. Population trends for 17 species were documented. Rapid increase in numbers of Turdus pilaris, Corvus cornix and Phoenicurus phoenicurus and decrease of Pica pica were recorded.