Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.
Department of Forestry and Environmental Conservation, Clemson University, Clemson, South Carolina, USA.
Ecology. 2022 Feb;103(2):e03600. doi: 10.1002/ecy.3600. Epub 2021 Dec 16.
Theory on intraguild killing (IGK) is central to mammalian carnivore community ecology and top-down ecosystem regulation. Yet, the cryptic nature of IGK hinders empirical evaluations. Using a novel data source - online photographs of interspecific aggression between African carnivores - we revisited existing predictions about the extent and drivers of IGK. Compared with seminal reviews, our constructed IGK network yielded 10 more species and nearly twice as many interactions. The extent of interactions increased 37% when considering intraguild aggression (direct attack) as a precursor of killing events. We show that IGK occurs over a wider range of body-mass ratios than predicted by standing competition-based views, with highly asymmetrical interactions being pervasive. Evidence that large species, particularly hypercarnivore felids, target sympatric carnivores with a wide range of body sizes suggests that current IGK theory is incomplete, underestimating alternative competition pathways and the role of predatory and incidental killing. Our findings reinforce the potential for IGK-mediated cascades in species-rich assemblages and community-wide suppressive effects of large carnivores.
种间竞争理论是哺乳动物食肉动物群落生态学和自上而下的生态系统调节的核心。然而，种间竞争的隐蔽性质阻碍了经验评估。利用一种新的数据源——非洲食肉动物种间攻击性的在线照片，我们重新审视了关于种间竞争的程度和驱动因素的现有预测。与开创性的综述相比，我们构建的种间竞争网络增加了 10 个物种和近两倍的相互作用。当将种内攻击（直接攻击）视为杀戮事件的前兆时，相互作用的程度增加了 37%。我们表明，种间竞争发生在比基于竞争的观点预测的更广泛的体重比范围内，具有高度不对称的相互作用是普遍存在的。大型物种，特别是超肉食性猫科动物，针对具有广泛体型的同域食肉动物的证据表明，目前的种间竞争理论是不完整的，低估了替代竞争途径和捕食性和偶然杀戮的作用。我们的研究结果加强了种间竞争介导的物种丰富组合中的级联效应和大型食肉动物对整个社区的抑制作用。
