環境

一般研究成果リスト

Detail of Grant Awarded General Researches

Project

Reproduce of the bird census for Tama River

General
Research
No.255
Principal
Investigator
Sumiko HASUO
Affiliation Bird census group for Tama River
Research
Summary

The Keihin Office of The Ministry of Construction requested a census of bird numbers be undertaken along the Tama River in 1976 and again in 1986. These censuses were undertaken every month from June 1976 to May 1977 and September 1986 to August 1987 from the river mouth (0km) to Mannen-bashi, Ome City (61.8km).We attempted to replicate the census using a method as close as possible to that used previously so results can be compared with those from the past. Our census work was undertaken every month from June 2019 to March 2020 and April May 2021. The results of our census show 52-80 bird species and 5696-13206 individuals were recorded per month with a total of 122 species over the 12 months. The number of both species and individuals was higher from October to March, and lower from May to September. Compared to previous censuses the number of ducks and gulls is a lot less. Waders have declined significantly since 1976 and almost disappeared. On the other hand, birds of prey and some of the song birds which inhabit hills and groves have shown an increase in numbers. The birds of wetlands, meadows and barren land have almost disappeared along the Tama River. This applies especially to Japanese Quail, Ruddy Crake and Painted Snipe all of which may have been breeding in 1976. This situation applies not only along the Tama River but also to other places around Tokyo Bay.


Collaborators

Naoya MASUDA
Nozomu MITARAI
Hiroshi KAWACHI
Futoshi INOUE
Yurika TOKUNAGA
Ryotaro SUZUKI

Full Text