The Present Status and Issues of the Specified Wildlife Conservation and Ma Gement Plans for the Asiatic Black Bear in the Western Chugoku Mountains, Japan

27 Mar The Present Status and Issues of the Specified Wildlife Conservation and Ma Gement Plans for the Asiatic Black Bear in the Western Chugoku Mountains, Japan

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Abstract

西中国地域のツキノワグマUrsus thibetanusの「特定鳥獣保護管理計画」は，第一期（2003～2006年度）と第二期（2007～2011年度）とも，広島県，島根県および山口県の三県で共通の指針の下に策定された．生息頭数調査は，個体の捕獲による標識再捕獲法を用いて2回実施され，1999年当時は約480頭，また2005年当時は約520頭と推定された．有害捕獲は1960年代から始まったが，2000年代に入ると年平均100頭以上へと急増した．とくに，大量出没した2004年には239頭，2006年には205頭にも達した．1996～1999年に比べて2000～2006年は，高齢個体も多数捕獲される傾向にあったが，捕獲個体の性比には変化はなかった．三県の放獣率や除去頭数の差は，地域によって異なったが，これは地域住民や行政の意識の違いに起因すると考えられた．放獣個体の再捕獲率は低かったが，学習放獣による奥地への定着や被害の再発防止効果は十分に検証できなかった．今後は，個体群のモニタリングの継続，錯誤捕獲の減少，地域住民への普及啓発の努力などがいっそう必要である．

English Abstract

Specified Wildlife Conservation and Ma gement Plans for the Asiatic black bear, Ursus thibetanus, in the western Chugoku Mountains, Japan, were executed in 2002 and several investigations were carried out in Hiroshima, Shimane, and Yamaguchi Prefectures. Bear population sizes estimated by the mark-recapture method were 480 in 1999 and 520 in 2005. The number of bears killed as nuisances has increased since the 1960s, especially in 2004 and 2006, when unusually high number of bears intruded into residential areas (239 individuals were killed in 2004 and 205 individuals in 2006). Proportio tely more older bears were captured in 2000–2006 than in 1996–1999, with no remarkable change in the sex ratio. Both the number of bears killed and the ratio of releases of captured bears differed among the regions. Differences in understanding of bear conservation and biology by local inhabitants and governments could be a reason of this. Although the recapture ratio of released bears was low, it was not clear whether these bears had learnt to avoid croplands. To conserve the bear population in this area more strictly, it is necessary to continue monitoring the population, to decrease the number of bears killed owing to accidental captures by traps for wild boars, and to promote public education on the conservation of wildlife.