The impact of trapping and handling activities on the breeding performance of Hooded Crows Corvus corone cornix

Abstract

Trapping of Hooded Crows Corvus corone cornix has been conducted for decades in an attempt to regulate population size. However, the effect of trapping activity on the breeding performance of crows is more or less unknown. In this study, trapping activities, involving Larsen-traps and decoy birds, were conducted at 14 Hooded Crow nest sites. Trapping was successful at eight nests, and a total of 12 individuals were caught. Hooded Crow breeding ceased within a few days following the trapping sessions and the territories were abandoned. This also happened at nests without trapping success, suggesting that the trapping activity itself, and not the actual trapping and handling of the birds, caused the cessation of breeding. The very high density of crow nests in the study area and the associated high risk of conspecific predation on the eggs is suggested as the most likely explanation for the observed effect on Hooded Crow breeding performance. © 2001 British Trust for Ornithology.