A study of the life history of Blue Magpie (I)

1. Breeding biology

Abstract

1. The breeding biology of the Blue Magpie Cyanopica cyana was studied in Nagano Prefectuae during 1962-1965.
2. The nesting succcss was analysed in regard to the kind of tree, nest-site, height from the ground and nesting distance (There was a tendency of group nesting).
3. Egg dates, incubation and nestling periods were analysed. The breeding season lasts from middle of May to late July, the average egg date was June 6, and no second brood was confirmed.
4. Clutch size ranged from 5 to 8 and the frequent sizes were 6-7. Brood size ranged from 1 to 7, most frequently 6. The flying success was highest from larger broods of 6-7 chicks.
5. Factors affecting the breeding rates during incubation and nestling periods were considered. The hatching rate was 68% and fledging rates were 30.5% from clutch and 66.5% after hatching.
6. Female only incubates and incubation and brooding constancies were calculated by Skutch's method. Male's feeding behavior to the female was described and feeding frequencies are given.
7. Size, shape and volume indexes of eggs were calculated.
8. The growth of chicks was described and growth rates of body weight, wing and tail lengths, tarsus and culmen were measured.