Effect of habitat diversity on breeding birds : comparison of farmland bird community in the region of Wielkopolska (w. Poland) with relevant data from other european studies

The breeding bird community of a 315 ha intensively used farmland in western Poland, consisting of arable fields and small part (ca. 5%) of margin habitats, was censused yearly from 1987 through 1997 by territory mapping. Its size was on average 318+-65 (SD) territories, belonging to 47+-4 species. Of the 71 stationary species, only 23 have been yearly present. Alauda arvensis, Motacilla flava, Emberiza citrinella, Sylvia communis and Acrocephalus palustris were the most abundant species throughout the period of the study. To determine the effect of land-use change of agricultural landscape on the abundance and diversity of breeding bird communities, the results of studies carried out on 12 similar large plots (1-10 km^2) in Central Europe were compared. The percent of margin habitats (hadgerows, ditches, small meadows, fallows etc.), when controlling for the effect of study plot size, is significantly correlated with number of breeding species (r=0.697) and total community density (r=0.899).