A study of the life history of Blue Magpie 6

Abstract

1. This sixth report on Cyanopica cyana is based on field observations of December 1963 to April 1968 and on a wide anquête on flock distribution in Nagano Prefecture. Movements of young birds were also studied.2. Local flock distribution was plotted on a 1/50.000 map of the prefecture, with an area of 19.600km2, sectioned into 49 of 1km2 squares. This plotting was based on data collected from 82 persons and one museum. The distributional pattern was centered in central Nagano-Ueda (particularly Nagano area) plain surrounded by mountain ranges, with scattered flocks to the peripheral foot zones. The interesting fact was that the distribution was restricted to the east (Nagano) side of the geologically important fossa magna. Local changes in distribution have also been noticed.3. Vertically, the distributional limit was found at 1, 600m on Kirigamine plateau from bottomland of 310m of altitude.4. No correlation of distribution with annual rainfall nor temperatures was found and it was distributed even in the districts with snowfall of 3m.5. Habitat environments included human habitation area, orchards and both broad and needleleaved woods, but with special preference to the combinations of human habitation with orchards or woods surrounding houses.6. The movement area of fledged young birds was limited in the diurnal activity range of the flock they belonged to. They were recorded within 20-570m from the nest.7. Birds ringed as nestlings were recovered after 0.5-20.5 months and there was no correlation of their dispersal distances and periods elapsed.