Breeding of the Rook (Corvus frugilegus) in the Czech Silesia – the past and the present / Hnízdění havrana polního (Corvus frugilegus) v Českém Slezsku – historie a současnost

A historical survey was compiled of Rook (Corvus frugilegus) rookeries in the Moravian- Silesian region based on literature and private data covering period 1945-2015. Altogether, eighteen rookeries have been documented. During the second half of the 20 century the numbers of the Rook population in the Czech Silesia increased slowly from zero to ca. 500 breeding pairs, but the number of rookeries has decreased at the latest after 1990. Since 2000, probably only two local Rook's breeding sites exist in the town of Opava and Ostrava and only Rook's population inhabits Opava seem to be stable. It cannot be excluded that the extinction of the Silesian rookeries in the 1990s is a temporary phenomenon, whose consequence will be a further increase in the mean rookery size in town of Opava.