Breeding performance of the Azure-winged Magpie Cyanopica cyanus in South Korea

The azure-winged magpie Cyanopica cyanus is a social corvid breeding in colonies, and known as single-brooded in the cooperatively breeding system. Although they are easily found throughout Korea, there is little information about the breeding ecology of this species. For more advanced future study of this species, we conducted a study of the breeding performance of this species in two consecutive breeding seasons (April~June, 2014~2015). In this study, we monitored 72 breeding nests in order to investigate the schedules of breeding events, such as timing of laying, clutch size, hatching size, brood size and fledging dates, and the breeding success of two study populations of the azure-winged magpie. In this study, the clutch size varied within a population, ranging from 5 to 9 eggs and all clutches were laid from late April to late May. Parents incubated for 17~18 days. The brood size ranged from 3 to 8 chicks, and the nestlings were provisioned for about 17 days (mean±SD= 17.38±1.70). The breeding success of two populations was about 70%, showing similar results as in earlier studies. Predation was a main factor affecting breeding failures of these populations.