Breeding biology and ecology of Whinchat Saxicola rubetra on abandoned farmland of Opole Province (SW Poland)

摘要

In 2003-2007 the breeding biology and ecology of Whinchat Saxicola rubetra were investigated on the 500 ha mosaic agricultural landscape (cropland, abandoned cropland, meadows, pastures and young pine plantations) in SW Poland. In the area of uncultivated fields, meadows and pine plantations 36, 34, 31,27 and 28 pairs bred consecutively in particular seasons of the study period. Most nests were situated in the abandoned fields in the grass and tansy Tanacetum vulgare. In the studied population the median date of egg-laying commencement fell on the 16th May. The first young fledged at the end of May. The average clutch size was 6.2 eggs (SD=0.8). The hatching success amounted to 76%. The average breeding success was 4.17 (n=l 17, SD=2.62) per nest, and 5.6 (n=87, SD=1.04) per successful pair. The overall breeding success was 74.1% (Mayfield method). The main reason behind the brood loss was predation (76.7% of all losses).