Przemysław Żurawlew, Paweł Czechowski, Łukasz Ławicki
Ornis Polonica 2010, 51: 262–274
https://doi.org/10.12657/ornis.2010.4.2
Abstract: This paper summarises the occurrence of the Carrion Crow Corvus corone in Poland basing on literature data as well as information from about 190 bird observers. The data cover the period from 19th century up to 2009. Hybridisation zone of the Carrion Crow and Hooded Crow C. cornix is situated in Germany and the Czech Republic. Therefore most breeding attempts of Carrion Crows and observations of non-breeding individuals have been recorded in western Poland. The only breeding record of the Carrion Crow pair occurred in 1890, but 9 cases of mixed broods of the Carrion and Hooded Crow have been found. Additionally, two broods at which at least one parent was Carrion Crow were recorded. Four times probable mixed breeding pairs were observed. Three nests belonged to the hybrids of C. corone × C. cornix and Hooded Crows. At one nest both parents were probably hybrids. In 19th century and first half of the 20th century Carrion Crow was recorded regularly but extremely rarely almost in the whole Poland. A marked increase since the 1980s has resulted probably from greater activity of bird observers. In 1954–2009 a total of 436 observations (612 ind.) of Carrion Crows were made, including 363 records (83%) from western Poland (Silesia, Lubuskie region, Wielkopolska region and Pomerania), while records from eastern Poland (east of the Vistula River) were very rare. Carrion Crows were observed mostly in spring (35% of records) and autumn (32%), while winter (18%) and summer records (15%) were much more seldom. In most cases up to 3 ind. were observed (96%), and the largest flocks comprised 9 birds. Carrion Crows were observed generally unaided (80% obs.), sometimes accompanied by Hooded Crows or (less often) by other corvids. Two individuals of Carrion Crow, ringed in Germany and Belgium, were subsequently caught in Poland, 434 km and 1010 km from the ringing site, respectively.
