Forest environment of the roosting sites of carrion crow (Corvus corne orientalis Eversmann) in the basin of the Tenryu River, Nagano Prefecture [Japan]
2007
Arase, T.(Shinshu Univ., Minamiminowa, Nagano (Japan). Faculty of Agriculture) | Kano, G. | Kumagai, M.
The autumn-winter roosting sites of carrion crow (Corvus corne orientalis) were observed in the basin of the Tenryu River, southern part of Nagano prefecture. From October 2005 to March 2006 and from October 2006 to January 2007, we chased the groups of crows from 2 hours to sunset, until they settled down in the roosting site. Eight roosting sites with hundreds to over 1000 crows were detected, which lay mostly on the river terraces and the slopes were facing between east and south. The vegetation included 3 types, without vegetation, Japanese red pine and deciduous forest, and Japanese red cedar and Japanese timber bamboo forest. The forests were generally enclosed with dense forest ridges of lianas and herbaceous plants, but the forest floors were scarcely covered with plants. Concerning the changes in the distribution of roosting sites, the comparison with the previous reports showed that the number of roosting cites seemed to be increasing, and they moved to urban area from mountainous zone.
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