Detail of Grant Awarded Academic Researches


Ecological study of Japanese Weasel (Mustela itatsi) in Tamagawa River by radio-telemetry method

Hideo Higashi
(at that time)
Representative, Wildlife Management Office

Green space provides habitat for wild life, and such green space is rapidly decreasing not only in the 23 wards of Tokyo , but also in the Tama Region.  However, a lot of green spaces still remain in the river terraces of the Tamagawa River, which runs between Tokyo Prefecture and Kanagawa Prefecture , while areas around the river have been transformed into residential and industrial areas.  In the river terraces, there are a few illegal agricultural lands, and lawn areas and parks for recreational purposes, such as baseball grounds and golf courses.  But in most cases, the river terraces are used in their natural state, for example, by those who enjoy walking or fishing.  In any case, the areas are seldom used at night.  It can be said that it is thanks to the Tamagawa River that the natural beauty that is seen around the Okutama Region can also be seen in the metropolitan area.

This study examined the ecology of Mustela itatsi [Japanese weasel] inhabiting the river terraces of the Tamagawa River .  Then, we evaluated the environmental conditions based on the habitat of Mustela itatsi, and discussed the significance of the natural environment in river terraces in Tokyo and Kanagawa prefectures.

We believe that understanding the habitat of a medium-size mammal (Mustela itatsi, in this case), living in a natural setting (river terraces, in this case) that still exists in metropolitan Tokyo and provides a habitat for wild life, can be used as a new indicator of the environmental conditions of the region.

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