環境

一般研究成果リスト

Detail of Grant Awarded General Researches

Project

Survey to confirm the inhabitation status of owls in the Tama River Basin

General
Research
No.251
Principal
Investigator
Hiroo ITAYA
Affiliation
(at that time)
Tama River Basin Owl Survey Study Group
Research
Summary

In various areas of Tokyo, the inhabitation of owls has been confirmed, but their actual status has not yet been studied, such as their whereabouts and numbers.

In order to shed light on this issue, the authors conducted a survey in FY2019 and FY2020 to find out the inhabitation distribution of owls in the Tama River Basin, both in Tokyo and Kanagawa, which aimed to provide basic data needed for protecting the rare species in Tokyo.

We selected 109 standard grid squares (third-order grid unit) to investigate using random sampling from grid squares in the Tama River Basin, and used the callback method to determine the inhabitation status of owls in Tama River Basin.

Through the study, we were able to confirm inhabitation of owls in 29 grid squares.

Categorizing the surveyed grids into mountains, hills, and urban areas, the inhabitation of owls was confirmed in 10 out of 37 squares among mountains, 13 out of 24 in hills, and 6 out of 28 in urban areas.

It should be noted that among the grids in the 23 Wards of Tokyo, no owls were found.


Collaborators

Daisuke SAKAMOTO


Full Text