Sato, Y., Mano, T. & Takatsuki, S. 2005: Stomach contents of brown bears Ursus arctos in Hokkaido, Japan. - Wildl. Biol. 11: 133-144.
We determined the seasonal food habits of brown bears Ursus arctos in three regions of Hokkaido, Japan, over eight years (1991-1998) by analysing the stomach contents of 556 bears killed for nuisance control or sport hunting. Seasonally dominant food items changed from herbaceous plants (61-80% in volume) in spring, to herbaceous plants (53-97% in volume) and ants (0-18% in volume) in early summer, crops (32-46% in volume) and herbaceous plants (26-31% in volume) in late summer, and berries (25-39% in volume), acorns and nuts (8-16% in volume) in autumn. These diet shifts were consistent among the three investigated regions. Crop depredation by brown bears in late summer occurred extensively in Hokkaido and was probably driven by a shortage of alternative food sources during this season. The proportion of sika deer Cervus nippon in the diet increased during the 1990s in eastern Hokkaido (25.2% in frequency), where bears consumed deer throughout the year. Bears probably acquired deer meat from carcasses left in the fields after the deer were shot for nuisance control and sport hunting. In the Oshima Peninsula of southern Hokkaido, bears consumed large amounts of anthropogenic waste (16% in frequency).
Key words: anthropogenic waste, carcass, Cervus nippon, crop damage, diet, Japan, Ursus arctos
Yoshikazu Sato*, Laboratory of Wildlife Biology, Department of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan - e-mail: ysato@brs.nihon-u.ac.jp
Tsutomu Mano, Wildlife Section, Nature Conservation Department, Hokkaido Institute of Environmental Sciences, Sapporo, 060-0819, Japan - e-mail: mano@hokkaido-ies.go.jp
Seiki Takatsuki, University Museum, The University of Tokyo, Tokyo, 113-0033, Japan - e-mail: taka@um.u-tokyo.ac.jp
*Present address: Department of Forest Science and Resources, College of Bioresource Sciences, Nihon University Kameino 1866, Fujisawa-city, Kanagawa, 252-8510, Japan
Corresponding author: Yoshikazu Sato
Received 8 September 2003, accepted 25 March 2004
Associate Editor: Henryk Okarma