Data from: Response of moose hunters to predation following wolf return in Sweden

Background: Predation and hunter harvest constitute the main mortality factors affecting the size and dynamics of many exploited populations. The re-colonization by wolves (Canis lupus) of the Scandinavian Peninsula may therefore substantially reduce hunter harvest of moose (Alces alces), the main prey of wolves. Methodology/Principal findings: We examined possible effects of wolf presence on hunter harvest in areas where we had data before and after wolf establishment (n = 25), and in additional areas that had been continuously exposed to wolf predation during at least ten years (n = 43). There was a general reduction in the total number of moose harvested (n = 31,827) during the ten year study period in all areas irrespective of presence of wolves or not. However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves. The reduction in harvest was larger in small (500-800 km2) compared to large (1,200-1,800 km2) wolf territories. In areas with newly established wolf territories moose management appeared to be adaptive with regard to both managers (hunting quotas) and to hunters (actual harvest). In these areas an instant reduction in moose harvest over-compensated the estimated number of moose killed annually by wolves and the composition of the hunted animals changed towards a lower proportion of adult females. Conclusions/Significance: We show that the re-colonization of wolves may result in an almost instant functional response by another large predator—humans—that reduced the potential for a direct numerical effect on the density of wolves’ main prey, the moose. Because most of the worlds’ habitat that will be available for future colonization by large predators are likely to be strongly influenced by humans, human behavioural responses may constitute a key trait that govern the impact of large predators on their prey.研究背景：捕食作用与人类狩猎收获是影响诸多经人类开发利用的种群的种群规模与动态的核心死亡因子。因此，灰狼（Canis lupus）对斯堪的纳维亚半岛的重新定居，可能会大幅降低其主要猎物——驼鹿（Alces alces）的猎人狩猎收获量。研究方法与主要结果：我们针对两类区域分析了灰狼存在对猎人狩猎收获的潜在影响：一类是具备灰狼定居前后观测数据的区域（共25处），另一类是至少连续10年持续受到灰狼捕食影响的区域（共43处）。在为期10年的研究周期内，所有区域的总驼鹿收获量（合计31827头）均出现普遍下降，无论区域内是否存在灰狼。但相较无灰狼的对照区域，灰狼领地内的狩猎收获量降幅更为显著；且相较于大型（1200-1800 km²）灰狼领地，小型（500-800 km²）灰狼领地内的收获量降幅更大。在新近建立灰狼领地的区域，驼鹿管理策略对管理者（狩猎配额）与猎人（实际收获量）均呈现适应性调整特征。此类区域中，驼鹿狩猎量的即时下降幅度超出了灰狼每年预估的猎杀驼鹿数量，且被猎捕动物的种群构成发生变化，成年雌性个体占比降低。研究结论与意义：本研究证实，灰狼的重新定居可引发另一大型捕食者——人类——产生近乎即时的功能响应，该响应削弱了灰狼对其主要猎物驼鹿种群密度产生直接数量效应的潜力。由于未来可供大型捕食者拓殖的全球多数生境都将受到人类活动的强烈影响，人类的行为响应可能是决定大型捕食者对其猎物种群影响程度的关键因素。