Seasonal changes of time and space distribution, and daily activity pattern of yeso sika deer (Cervus nippon yesoensis) in eastern Hokkaido, Japan

エゾシカの時空間的な行動特性はエゾシカの管理において重要な情報であり，自然植生の多い地域で調べられているが，牧草地など人間が利用する土地の多い地域での知見は多くない。本研究は，エゾシカの日周活動および空間分布の季節変化を明らかにすることを目的として，２０１０年から２０１４年に北海道東部の牧草地と隣接する森林においてカメラトラップ，ライトセンサス，目撃調査を行った。エゾシカの日周活動は日没・日の出の時間帯にピークが認められ，日中の活動性は春季に比べて秋季が低かった。日中の空間分布は，春季と夏季では牧草地に接する林縁で密度が高く，夏季よりも春季で特に高かった。これは，夏季にはエゾシカの利用場所が分散していることを示しているのかもしれない。日没後の空間分布は，春季と秋季に牧草地に接する林縁で密度が高かった。また，エゾシカは自動車の通行などの人間活動を避けるために，交通量の少ない道路が通る牧草地に接する研究林東側の林縁を選択的に利用していると推測された。Time and space behavior characteristic of yeso sika deer (Cervus nippon yesoensis) in natural vegetation area is the important information for management of yeso sika deer and have reported previously. However there is little information in the human utilizing area such as pasture. In order to clarify the seasonal changes of time and space distribution, and daily activity pattern of yeso sika deer, infrared-triggered camera sighting, spotlight census and road census were conducted during 2010-2014 in the forest area surrounded by pasture on eastern Hokkaido. We found that the daily activity of yeso sika deer was the most around dusk and dawn compared to the other time. In spring and summer, the density distribution of yeso sika deer was high at the forest edge borders on the pasture. However the density distribution in summer was lower than in spring. These results indicate that the habitat selection of yeso sika deer was scattered in summer. Around dusk in autumn, the density estimation was high at the forest edge borders on the pasture. To avoid the human activities such as vehicle, yeso sika deer selectively use the east side forest edge borders on the pasture where traffic was fewest