Acta Zoologica Cracoviensia, 21() 1976
Rooks Corvus frugileus Linnaeus, 1758, in one of the Cracow Parks
Abstract:
The dynamics of nesting of a colony studied from the year of its origin (1969) to the spring of 1975 is presented. The rate of natural decay of its nests and also four phases of its rebuilding and development have been established. The full maintenance of the life cycle of the colony depends to a great extent 1) on the interest some Rooks take in the nests in autumn and winter and 2) on passive cooperation which forms a base for the drive that brings these birds to the park. The influence of the climate on the breeding season is discussed and the effect of the knocking-off of nests has been related to the hormonal state of the birds. Autumnal knocking-off of nests is proposed as a more humane attempt to liquidate annoying colonies.
