著者

中下 留美子 後藤 光章 泉山 茂之 林 秀剛 楊 宗興

出版者

The Mammal Society of Japan

雑誌

哺乳類科学 = Mammalian Science (ISSN:0385437X)

巻号頁・発行日

vol.47, no.1, pp.19-23, 2007-06-30

被引用文献数

2

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An adult male Asiatic black bear (<i>Ursus thibetanus</i>), 105 kg in body weight and 130 cm in total length, was captured at a fish farm in Miyadamura village, Nagano Prefecture, Japan in June 2005, due to its nuisance activity. We analyzed δ¹³C and δ¹⁵N in the hairs and plasma of the bear and in the muscles of rainbow trouts (<i>Oncorhynchus mykiss</i>) at the farm to discern whether the bear was actually involved in the farm damages. Both δ¹³C and δ¹⁵N values in the hairs and plasma were similar to those in rainbow trout muscles, confirming that the bear indeed ate a considerable number of the farm's rainbow trouts. The δ¹³C and δ¹⁵N values of serum were closer to those of the trout muscles than those of the hairs, indicating that the bear depended heavily on trouts in the spring of 2005 in comparison with the previous year. Moreover, stable isotope levels in the tips of the hairs were closer to those of trout muscles than those at the bases of the hairs. This suggests that the bear depended much more heavily on trouts in the previous spring than in the previous fall.<br>