Stable breeding despite variable feeding in two sympatric auk (Alcidae) species

Capsule Despite substantial inter-annual and inter-specific variance in the composition of chick diet, the breeding success of Guillemots (Common Murres) Uria aalge and Razorbills Alca torda remained constant from 2008 to 2010. Aims To examine inter-specific and inter-annual differences in breeding success, chick provisioning behaviour and predation between two sympatric auk species. Methods Focal observations of breeding auks at Rathlin Island,...