Predators in natural fragments: foraging ecology of wolves in British Columbia's central and north coast archipelago
Predators in natural fragments: foraging ecology of wolves in British Columbia's central and north coast archipelago
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DOI：
10.1111/j.1365-2699.2004.01141.x
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发表时间：
2004-11-01
影响因子：
3.9
通讯作者：
Paquet, PC
中科院分区：
文献类型：
--
作者：
Darimont, CT;Price, MHH;Paquet, PC
目的 破碎区域中的捕食者 - 猎物动态可能受到景观空间特征的影响。尽管对这些过程知之甚少，但日益破碎的地球凸显了预测其后果的紧迫性。因此，我们的目的是研究一种顶级哺乳动物捕食者——狼（Canis lupus）在群岛环境中的觅食行为。
地点 加拿大不列颠哥伦比亚省的大陆及邻近群岛；这是一个基本原始且自然破碎的景观，有大小和隔离程度各异的岛屿。
方法 我们在2000年和2001年夏季对30个大陆流域和29个岛屿的狼粪便进行采样，并识别猎物残骸。我们研究了广泛的地理模式以及详细的生物地理变量（面积和隔离指标）与所消耗猎物的关系。对于岛屿数据，我们使用赤池信息准则来指导广义线性回归模型的选择，以预测粪便中黑尾鹿（主要猎物；Odocoileus hemionus）出现的概率。
结果 黑尾鹿在每堆粪便出现频率（63%）和每件物品出现频率（53%）指数中是最常见的种类，约占哺乳动物生物量的63%。狼在靠近大陆的岛屿上（每件物品出现频率为65%）比在大陆（39%）和外岛（45%）捕食更多的鹿，在大陆和外岛，其他有蹄类动物（仅在大陆）和小型哺乳动物取代了鹿。在岛屿上，检测到鹿的概率主要受岛屿到大陆的距离影响（不受面积或陆地间距离影响），这表明鹿从源种群重新定居的能力有限是一种因果机制。
主要结论 尽管采样时间有限，但岛屿之间的一致模式表明，孤立碎片中的种群动态不太稳定，并可能导致猎物的枯竭。这可能对理解孤立环境中的捕食者 - 猎物群落、关于狼 - 鹿系统的争论以及温带雨林中的伐木活动和保护区设计具有重要意义。
Aim Predator-prey dynamics in fragmented areas may be influenced by spatial features of the landscape. Although little is known about these processes, an increasingly fragmented planet underscores the urgency to predict its consequences. Accordingly, our aim was to examine foraging behaviour of an apex mammalian predator, the wolf (Canis lupus), in an archipelago environment.Location Mainland and adjacent archipelago of British Columbia, Canada; a largely pristine and naturally fragmented landscape with islands of variable size and isolation.Methods We sampled 30 mainland watersheds and 29 islands for wolf faeces in summers 2000 and 2001 and identified prey remains. We examined broad geographical patterns and detailed biogeographical variables (area and isolation metrics) as they relate to prey consumed. For island data, we used Akaike Information Criteria to guide generalized linear regression model selection to predict probability of black-tailed deer (main prey; Odocoileus hemionus) in faeces.Results Black-tailed deer was the most common item in occurrence per faeces (63%) and occurrence per item (53%) indices, representing about 63% of mammalian biomass. Wolves consumed more deer on islands near the mainland (65% occurrence per item) than on the mainland (39%) and outer islands (45%), where other ungulates (mainland only) and small mammals replaced deer. On islands, the probability of detecting deer was influenced primarily by island distance to mainland (not by area or inter-landmass distance), suggesting limited recolonization by deer from source populations as a causal mechanism.Main conclusions Although sampling was limited in time, consistent patterns among islands suggest that population dynamics in isolated fragments are less stable and can result in depletion of prey. This may have important implications in understanding predator-prey communities in isolation, debate regarding wolf-deer systems and logging in temperate rain forests, and reserve design.