環境

一般研究成果リスト

Detail of Grant Awarded General Researches

Project

Bat fauna surveys by using harp traps as well as mist nets of forests along Tama River in Tokyo and an attempt to build a bat call library

General
Research
No.224
Principal
Investigator
Tatsuya Kasahi
Affiliation
(at that time)
Tokyo Bat Research Group
Research
Summary

In 2014, because of a delay in receiving wildlife permits, a survey of bats and a census of individuals using an abandoned tunnel in Okutama and an abandoned mine in Ome was performed monthly. The result confirmed use by the horseshoe bat, little Japanese horseshoe bat, eastern long-fingered bat, and Ussuri tube-nosed bat but did not confirm use as a birthing and nursing site nor as a wintering site.


In 2015, mist nets and harp traps were used 16 times to implement capture and research and once for protection at nine sites in Ome, Akiruno, and Hinohara. The end result was the capture of six horseshoe bats, one little Japanese horseshoe bat, 31 Asian parti-colored bats (of them, 11 for protection), five eastern long-fingered bats, and five Ussuri tube-nosed bats. These were the first such findings recorded in several municipalities. A simple comparison is impossible due to the infrequent captures, but the effectiveness of introducing harp traps for trapping low-flying bats was evident. Bat call samples were obtained from 9 individuals, but the number of samples was insufficient to examine the trend of the Okutama mountain region bats fauna.


The Okutama mountains (in Tokyo Metropolis) are reported to have 53 limestone caverns and numerous man-made caves, although the exact number is unknown. In order to consider the protection and conservation of bats in caves in the Okutama mountains, the status of their use of these limestone caverns and man-made caves must be carefully researched. Such study if carried out would be the first to track the dynamics of bats in these caves.


Of bats flying in the forest, those captured were banded during the capture and research. If these individuals are re-captured within the Okutama mountains or in some other region, some answers will be provided about their range of movement and longevity. Although the capture frequency was not high, by repeating this research, it will become clear which bats live in which locations in the Okutama mountains, and this is expected to lead to a proper evaluation for protection and conservation. In addition, this time we have attempted to collect a bat call library. We expect that in the future, by collecting enough samples, we will be able to identify which bats are using which areas without the need for capturing.


Collaborators

MINESHITA Koo・

URANO Morio・

TEZUKA Makito・

SUGIE Toshikazu

MATSUYAMA Ryuta・

HASEGAWA Sara・

YOSHIBA Seina・

KONISHI Etsuko


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