Marcin Tobółka, Paweł Szymański, Stanisław Kuźniak, Sławomir Maćkowiak, Szymon Kaczmarek, Janusz Maliczak, Waldemar Michalak, Janusz Ratajczak, Paweł Sieracki, Janusz Stępniewski
Ornis Polonica 2011, 52: 107–116
https://doi.org/10.12657/ornis.2011.2.3
Abstract: The study describes numbers and distribution of Rook colonies in agricultural landscape of the Leszno Province (western Poland). The research was conducted in 2010 within the area of 4 154 km². A total of 35 colonies were found, including 1706 nests (density of 41 pairs/100 km²). In comparison to the previous census from 2002, the number of colonies declined by nearly 40%, while the number of nests declined by approximately 35%. All rookeries were located within human settlements: 24 (69%) colonies were found in the cities or big towns, 5 (14%) in small towns and 6 (17%) in villages. The average colony in 2010 consisted of 48.7 (SD=65.4) nests, and was slightly bigger than in 2002 (45.7; SD=85.5 pairs). These results provide further evidence for the continuing breeding population decline of the Rook over the period 1986–2010 in the study area.
