The role of the wolf in shaping a multi-species ungulate community inthe Italian western Alps

摘要

The impact of predation by wolves on prey populations was analysed in a portion of the western Alps characterized by a rich wild ungulate community. The number of wolves ranged from 7 to 15 (1.7-2.9 wolves/100 km~2) during the study period (2000-2001). The diet of wolves mainly consisted of wild ungulates. Red deer and roe deer were the staple prey, while chamois was consumed less despite its high density. From 2000 to 2002, wolves annually removed 20-34 red deer, 21-58 roe deer, and 7-14 chamois per100km~2. These amounts were equivalent to 19-51% of the annual mortality of red deer, 6-28% of roe deer and 6-9% of chamois. Additionally, hunting accounted for 58-94% of the annual mortality of red deer, 18-29% of roe deer and 22-43% of chamois. Othermortality factors (i.e. traffic accidents, disease, poaching) constituted a small percentage of the annual mortality of red deer (5-6%), roe deer (6-9%) and chamois (1%). During the study period, the density of prey animals was stable. Wolf predation didnot seriously affect ungulate populations. The role of wolves on wild ungulate populations in the Susa Valley seemed to be compensatory.