Parasitic common goldeneye ( Bucephala clangula ) females lay preferentially in safe neighbourhoods

Abstract

Abstract Nest predation has been suggested as anexplanation of the adaptive significance and evolutionof conspecific brood parasitism, an alternative reproduc-tive tactic pursued by females in several animal taxa. Iused new nest boxes that contained only decoy eggs andwere erected on lakes differing in real nest predation riskto test this hypothesis in the common goldeneye (Bu-cephala clangula), a hole-nesting duck. I used brokeneggs to simulate predation risk of the boxes to determineif parasites having no previous experience with the boxesdiscriminate between seemingly safe and risky nest sites.Parasites laid eggs in the experimental boxes indepen-dently of the simulated predation risk, suggesting thatthey do not use broken eggs or nest disarray as indicatorsof predation intensity. Parasites preferred experimentalboxes on lakes where real nest predation risk was low,supporting the nest predation risk hypothesis. Assumingthat females in high risk areas have had experience of nestpredation, they may take this into account in selectinghost nests.Keywords Bucephala clangula · Conspecific broodparasitism · Experience · Nest predation