The relationship between nest location and breeding success in the colonial nesting Azure-winged Magpie Cyanopica cyanus breeding in Japanese Yew Taxus cuspidata tree plantations

Abstract

ABSTRACT Capsule Azure-winged Magpies Cyanopica cyanus living in isolated plantations had higher nesting success away from habitat edges and lower breeding success away from conspecific nests. Aims The study aims to find the relationship between nest location and breeding success by measuring nest locations within two Azure-winged Magpie populations that breed in plantation environments with clear boundaries. Methods Two populations were selected in Gyeonggi-do, South Korea, with areas 11,392 m2 and 1,457 m2. These two plantations had a single species of tree, the Japanese Yew Taxus cuspidata, so breeding habitat was easily delineated. Breeding performance and breeding success were monitored daily. Distance between nests and distance to habitat edge were measured. Results Breeding success differed according to nest locations, and nests that were relatively distant from other neighbouring nests and that were closer to the edge of the breeding site had a higher risk of failure. Conclusions The results indirectly support Hamilton and Vine’s models, which assumed that individuals breeding close to the edge of the breeding group should have a higher risk of predation than those in the centre. It appears that the selection of nest location of Azure-winged Magpies may be affected by a social factor (i.e. colonial breeding in a cooperative breeding system) and an environmental factor (i.e. habitat edge effects).