Adaptive significance of the white pelage for brown bears in the Kunashiri Iland

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660130
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Forest science
• Research Institution: Rakuno Gakuen University
• Principal Investigator: SATO Yoshikazu 酪農学園大学, 農食環境学群, 教授 (60366622)
• Co-Investigator(Renkei-kenkyūsha): NAKASHITA Rumiko 独立行政法人森林総合研究所, 野生動物研究領域, 研究員 (00457839)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: ヒグマ / 毛色多型 / イニンカリグマ / 行動 / 食性 / カラフトマス / 北方領土 / 国後島

Outline of Final Research Achievements

White-colored brown bears live only in the Kunashiri and Etrofu Islands. We hypothesized that the white pelage color may provide an advantage for catching salmon. From the scat contents analysis, major food resources of brown bears in the Kunashiri and Etrofu Islands were herbaceous plants, salmon, and fruits. We found no individual differences in seasonal food habit estimated by the carbon- and nitrogen-stable isotope analysis. We examined the behavioral response of pink salmon for the different colors of experimenter (black or white) in river water. Pink salmon tended to keep larger distance from the experimenter with black cloths than with white cloths. We considered the white pelage color of bears have an advantage for catching salmon.

Free Research Field

野生動物生態学