Département de Biologie, Centre d'Études Nordiques and Centre de la Science de la Biodiversité du Québec, Université Laval, Pavillon Alexandre-Vachon, Quebec, Quebec, Canada.
Chaire de Recherche du Canada en Biodiversité Nordique, Centre d'Études Nordiques, and Centre de la Science de la Biodiversité du Québec, Université du Québec à Rimouski, Rimouski, Quebec, Canada.
J Anim Ecol. 2023 Dec;92(12):2373-2385. doi: 10.1111/1365-2656.14017. Epub 2023 Oct 10.
Indirect interactions are widespread among prey species that share a common predator, but the underlying mechanisms driving these interactions are often unclear, and our ability to predict their outcome is limited. Changes in behavioural traits that impact predator space use could be a key proximal mechanism mediating indirect interactions, but there is little empirical evidence of the causes and consequences of such behavioural-numerical response in multispecies systems. Here, we investigate the complex ecological relationships between seven prey species sharing a common predator. We used a path analysis approach on a comprehensive 9-year data set simultaneously tracking predator space use, prey densities and prey mortality rate on key species of a simplified Arctic food web. We show that high availability of a clumped and spatially predictable prey (goose eggs) leads to a twofold reduction in predator (arctic fox) home range size, which increases local predator density and strongly decreases nest survival of an incidental prey (American golden plover). On the contrary, a scattered cyclic prey with potentially lower spatial predictability (lemming) had a weaker effect on fox space use and an overall positive impact on the survival of incidental prey. These contrasting effects underline the importance of studying behavioural responses of predators in multiprey systems and to explicitly integrate behavioural-numerical responses in multispecies predator-prey models.
间接相互作用在具有共同捕食者的猎物物种中广泛存在，但驱动这些相互作用的潜在机制通常不清楚，我们预测其结果的能力也有限。影响捕食者空间利用的行为特征的变化可能是介导间接相互作用的关键近端机制，但在多物种系统中，关于这种行为-数量反应的原因和后果的经验证据很少。在这里，我们研究了共享共同捕食者的七个猎物物种之间复杂的生态关系。我们使用路径分析方法，在一个全面的 9 年数据集上，同时跟踪关键北极食物网物种的捕食者空间利用、猎物密度和猎物死亡率。我们表明，丰富的、聚集的、空间可预测的猎物（鹅卵）会使捕食者（北极狐）的家域大小减少两倍，这会增加当地捕食者的密度，并强烈降低偶然猎物（美洲金翅雀）的筑巢成功率。相反，具有潜在较低空间可预测性的分散周期性猎物（旅鼠）对狐狸空间利用的影响较弱，对偶然猎物的生存总体上有积极影响。这些对比鲜明的影响强调了在多猎物系统中研究捕食者的行为反应以及在多物种捕食者-猎物模型中明确整合行为-数量反应的重要性。
