Salo Pälvi, Korpimäki Erkki, Banks Peter B, Nordström Mikael, Dickman Chris R
Section of Ecology, Department of Biology, University of Turku, 20014 Turku, Finland.
Proc Biol Sci. 2007 May 22;274(1615):1237-43. doi: 10.1098/rspb.2006.0444.
Alien predators are widely considered to be more harmful to prey populations than native predators. To evaluate this expectation, we conducted a meta-analysis of the responses of vertebrate prey in 45 replicated and 35 unreplicated field experiments in which the population densities of mammalian and avian predators had been manipulated. Our results showed that predator origin (native versus alien) had a highly significant effect on prey responses, with alien predators having an impact double that of native predators. Also the interaction between location (mainland versus island) and predator origin was significant, revealing the strongest effects with alien predators in mainland areas. Although both these results were mainly influenced by the huge impact of alien predators on the Australian mainland compared with their impact elsewhere, the results demonstrate that introduced predators can impose more intense suppression on remnant populations of native species and hold them further from their predator-free densities than do native predators preying upon coexisting prey.
人们普遍认为外来捕食者对猎物种群的危害比本地捕食者更大。为了评估这一预期，我们对45个重复和35个非重复的野外实验中脊椎动物猎物的反应进行了荟萃分析，这些实验中对哺乳动物和鸟类捕食者的种群密度进行了操控。我们的结果表明，捕食者的来源（本地与外来）对猎物的反应有极显著影响，外来捕食者的影响是本地捕食者的两倍。此外，地点（大陆与岛屿）和捕食者来源之间的相互作用也很显著，表明在大陆地区外来捕食者的影响最强。尽管这两个结果主要受到外来捕食者在澳大利亚大陆的巨大影响与其在其他地方的影响相比的影响，但结果表明，引入的捕食者对本地物种的残余种群施加的抑制比本地捕食者捕食共存猎物时更为强烈，使它们离无捕食者密度更远。
