Breeding bird community of the Ogawa Forest Reserve, an old-growth deciduous forest in central Japan

摘要

The breeding bird community of the Ogawa Forest Reserve (OFR), an old-growth deciduous forest in central Japan, was surveyed and compared with those of similar forests on Honshu, the largest island of Japan. Of the 63 bird species observed, 51 were potential breeders within the OFR, and 31 of these had territories in the 12-ha study plot for at least I year during the 5 study years. Annual changes in the breeding community were small; the average total density was 491 pairs per 100 ha and the average number of species was 25.6. The Great Tit Parus major was the dominant breeding species, followed by the Willow Tit P. montanus, Narcissus Flycatcher Ficedula narcissina, Coal Tit P. ater, Varied Tit P. varius, and Ashy Minivet Pericrocotus divaricatus, a national red-listed species. Some local red-listed species, such as the Brown Flycatcher Muscicapa dauurica and White-backed Woodpecker Dendrocopos leucotos were also common in the OFR. The results suggest that the OFR harbors a breeding bird community similar to its original status. Cluster and ordination analyses indicated that the avifauna of the OFR was characterized more by the elevation than by the geographic location and thus represents the original bird species diversity of the low-montane beech forests of Honshu. As low-montane areas of Japan have been degraded in recent decades, the OFR provides a valuable indicator of bird species biodiversity for sustainable forest management.