Foraging variation of Asiatic black bears: evidence for individual differences in diet

2015 Fiscal Year Final Research Report

• Project/Area Number: 25850103
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Forest science
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: KOIKE Shinsuke 東京農工大学, (連合)農学研究科(研究院), 准教授 (40514865)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ツキノワグマ / 大型哺乳類 / 食性 / 個体差

Outline of Final Research Achievements

We recognized the individual foraging variation on the bears and the factors varied seasonally and yearly. In summer, when food availability is low for the bears, the older bears and males consume more food items of high δ13C values. In autumn, which is the hyperphagia period for the bears, most bears depended on more plant materials such as hard mast in the good mast years. On the contrary, in the years of poor mast years, getting enough hard mast took significant cost and most bears might consume more animal matter such as insects as an alternative food.
We conclude that there are individual foraging variation of bears during summer and autumn. Additionally, the difference of individual diet for the bears in summer might be influenced by the difference of body mass relevant to increasing age or sexual dimorphism. In contrast, the autumn diet of the bears might be similar within population but be varied according to temporal and spatial variation of food availability.

Free Research Field

生態学