丹沢山のスズタケ退行地域におけるニホンジカの越冬期の生息地利用

抄録

Vertical distribution of the wintering sika deer (Cervus nippon) population, current food biomass, and the percent composition of sasa grass in rumen contents of sika deer at Mt. Tanzawa were surveyed to evaluate the importance of sasa as a main component of sika deer winter habitat. The results were as follows; 1) high density, 53.1/km^2, and extremely concentrated distribution of the sika deer population were observed in February with little snow cover around the top of Mt. Tanzawa, 2) Sasa hayatae which occurs above 1, 300m in elevation was the only food plant which had a high biomass in the study area, 3) relatively high composition of sasa tissues in winter rumen contents collected around Mt. Tanzawa indicated that deer fed on S. hayatae as a staple food. The reasons why high density and concentrated distribution of sika deer population occurred were that deer used habitat where highly resistance sasa species such as S. hayatae were prevelant, rather than areas where widely distributed species such as Pseudosasa purpurascens were undergoing retrogression, namely in areas below 1, 300m in elevation.