A Decade Bird Survey in the Imperial Palace Area in Tokyo, April, 1965-March, 1975

Abstract

A ten-year monthly bird survey in the Imperial Palace area in Tokyo has been executed during April, 1965-March, 1975, with 130 censuses along a fixed 4.1km observation route during morning 2 hours from 9.30 a. m. The habitat included: 1. The Fukiage area, mainly wooded and grassy parts, with a pond, small reed shallow and a ditch, and 2. The Dokanbori area of upper and lower moats with steep wooded banks and a high wood-hill called Momijiyama. The avifauna of Fukiage area consisted of normal land birds, while water birds, ducks in winter and herons in summer, dominated in the Dokanbori bird community. They could be grouped into; 17 residents and wanderers, 25 winter visitants, 9 summer visitants, 26 summer transients and 15 casual winter visitants; in all 92 (with 1 subspecies and 1 hybrid) species of 15 Orders and 30 Families. The number of species and individuals were highest in autumn and then in spring, and were higher in winter than in summer, though this was disturbed by wintering ducks and colonial summer herons. The palace woodlands having been perfectly preserved isolated from city zone during the 10 years, the populations of resident birds have been kept stable with spring or autumn type seasonal increases characteristic to species. But, summer transients and winter visitors decreased owing to municipal developments of the surrounding areas. This survey has now entered the 2nd decade research period continued by Akio Sasagawa.