The Distribution and Size of Roosts of Crows Corvus macrorhynchos and Corvus corone in the Northwestern Part of Chiba Prefecture

Abstract

The distribution and size of roosts of crows Corvus macrorhynchos and Corvus corone were examined in the northwestern part of Chiba Prefecture from January 1990 to February 1990, and from October 1990 to February 1991. Five roosts were found in the study area, with a mean distance between neighboring roosts of 15.2km. The total number of crows gathering at the Konoyama roost was estimated to be about 2, 000-2, 600. The catchment area of the crows at the Konoyama roost was 70km². It was observed that they flew directly from foraging locations to their roosts.