Endangered and declining bird species of abandoned farmland in south-western Poland

In the end of the 1990ʹs the area of abandoned arable land in Poland amounted to ca. 2,000,000 ha, which constituted nearly 11% of the total farmland. A total of 21 bird species (average 5.0, range 1–12) was found to breed in abandoned farmland of Wrocław Plain (SW Poland, Lower Silesia Province). Between 1 and 94 pairs bred per field in 66 out of 67 study fields (average surface 5.0 ± 10.5 ha). Six species (Acrocephalus palustris, Saxicola rubetra, Sylvia communis, Miliaria calandra, Locustella naevia, Emberiza schoeniclus) represented some 83% the whole community. The number of pairs was positively correlated with the field size. The occurrence of a rich and diverse breeding bird fauna on older abandoned fields was conditioned by the presence of a well-preserved vegetation cover (Tanacetum vulgare, Solidago sp., Artemisia vulgaris) of the previous year.