Changes in the number of nest boxes destroyed by crows

Abstract

Crow species Corvus macrorynchus, C. corone in Japan have been known to physically damage nest boxes installed for passerines, essentially destroying the boxes so that they are unusable by the intended species. The frequency of nest box destruction by crows suddenly increased throughout the Japan in 1995. The activities reached their peak in 1996, and have decreased by half since 1997. In 2000, nest box destruction by crows had almost ceased. It is not known why the nest box destruction suddenly began and ended over the course of 5 years.