Behavioral change of a male Japanese black bear i Sept 2, 2011 4:46:44 GMT -9
Post by warsaw on Sept 2, 2011 4:46:44 GMT -9
in Ashio-Nikko Mts., central Japan
Yamazaki, Koji1(firstname.lastname@example.org), C. Kozakai2, S.Koike2, Y. Nemoto2, A. Nakajima2, Y. Umemura2 and T. Masaki3
1Ibaraki Nature Museum, Ibaraki, 306–0622, Japan
2 Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
3 Forestry and Forest Products Research Institute, Ibaraki, 305-8687 Japan
In the autumn of 2010, there was a mast failure, and the Japanese black bear intrusion into humanhabitation
was broadly occurred through Honshu Island. In the results, 2,304 bears were nuisancekilled,
and 118 people were injured by bears, including 4 deaths (as of 31 October 2010). This was 3rd
mass-intrusion that happened in the decade (In 2004: 109 people were injured by bears (including 2
deaths), and 2,021 bears were killed; in 2006: 145 people were injured by bears (including 3 deaths),
and 4,340 bears were killed), because of the bears traveled an extensive range in search of food
The extensive mast failure especially for Fagus crenata, F. japonica, and Quercus crispula was also
confirmed in our study area in 2010, in the Nikko National Park, central part of Honshu Island. One
of the GPS collared bears (MB69: male, age at 17 yr. old as of 2010) has moved out from his usual
home range in the end of August, and after some traveling, he has found a private fish farm where was
surrounded electric fence in the foothills, but it was being un-worked due to the current leaking.
When MB69 has habituated to the farm, he has drastically changed his daily activity pattern from
diurnal to nocturnal. Finally, MB69 has nuisance-killed on 28 August. Although other GPS tracked
bears have unusually lost their body weight in the autumn than the summer, MB69 has increased his
body weight for 24kg (BW=105kg) within a month than the summer.
This was suggested that mast failures could be one of the significant reasons for the conflicts, but it is
also as a result of a decline in bear avoidance effort in the foot hills due to aging of local residents.
Thus, there is a new generation of bears that do not fear people.