Bingham Ellen L, Gilby Ben L, Olds Andrew D, Weston Michael A, Connolly Rod M, Henderson Christopher J, Maslo Brooke, Peterson Charles F, Voss Christine M, Schlacher Thomas A
School of Science and Engineering, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia.
The ANIMAL Research Centre: Health + Ecology + Conservation, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia.
Oecologia. 2018 Oct;188(2):583-593. doi: 10.1007/s00442-018-4217-0. Epub 2018 Jul 6.
Introduced species may suppress or enhance ecological functions, or they may have neutral effects in ecosystems where they replace or complement native species. Few studies, however, have explicitly tested for these trajectories, and for the effect these might have for native species. In this study, we experimentally test the trajectory and scale of change in the function of 'carrion removal' at different carrion loads along ocean beaches in Eastern Australia that have different numbers of introduced red foxes (Vulpes vulpes) and several species of native raptors. We hypothesized that the 'positive' effect of foxes on carrion removal would be greatest at high carrion loads, because competition for resources between native and introduced species is lower. Scavenger abundance, fox occurrences, and carrion consumption by these species differed widely between locations and times. Despite distinct spatial differences in the structure of vertebrate scavenger assemblages, total carrion consumption was not significantly different between locations at any carrion load. This lack of variation in functional rates indicates potential functional plasticity in the scavenger assemblage and possible functional accommodation of red foxes. Neutral fox effects on ecological functions or the ecosystem more broadly are, however, very unlikely to extend beyond carrion consumption.
外来物种可能会抑制或增强生态功能，或者在取代或补充本地物种的生态系统中产生中性影响。然而，很少有研究明确测试这些轨迹，以及它们可能对本地物种产生的影响。在本研究中，我们通过实验测试了澳大利亚东部海滩上不同腐肉负荷下“腐肉清除”功能变化的轨迹和规模，这些海滩上引入的赤狐（赤狐属）数量不同，还有几种本地猛禽。我们假设，狐狸对腐肉清除的“积极”影响在高腐肉负荷下最为显著，因为本地物种和引入物种之间的资源竞争较低。这些物种的食腐动物丰度、狐狸出现情况以及腐肉消耗量在不同地点和时间差异很大。尽管脊椎动物食腐动物组合结构存在明显的空间差异，但在任何腐肉负荷下，不同地点之间的总腐肉消耗量并无显著差异。功能速率缺乏变化表明食腐动物组合可能具有功能可塑性，以及赤狐可能具有功能适应性。然而，狐狸对生态功能或更广泛生态系统的中性影响极不可能超出腐肉消耗范围。
