摘要

Rooks show a growing tendency to winter in cities. The aim of this study was to determine the influence of meteorological factors on the selection of feeding habitats and to discuss the diversity of feeding strategies in urban environments of different sizes and housing densities. The study was carried out in two cities in south-western Poland, Wroclaw and Brzeg (populations of 636,000 and 39,000, respectively), in the years 2004-2008. Nineteen research areas differing in housing density were controlled once a week. In multiple regression, the number of rooks feeding in urban environments showed a correlation with air temperature and the thickness of snow cover. The densities of feeding rooks were higher in urban environments than in agrocenoses. They were also higher in Wroclaw than in Brzeg, and in built-up areas than in undeveloped ones. Feeding groups were smaller in Brzeg than in Wroclaw. They were also smaller in built-up areas in Brzeg than in undeveloped ones. More rooks fed individually in Brzeg than in Wroclaw. The diversity in the frequency of individually feeding rooks in built-up and undeveloped environments was specific to each city. Rooks feeding in Brzeg were more active in searching for food than those in Wroclaw, and birds feeding on optimum, undeveloped feeding grounds were more active than those in built-up areas. In both cities, rooks were fed by humans, mainly in built-up areas.

  • 出版日期2013