Community Ecology Lab, Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
Nature-based Solutions Initiative, Department of Zoology, University of Oxford, Oxford, UK.
J Anim Ecol. 2020 Aug;89(8):1766-1774. doi: 10.1111/1365-2656.13239. Epub 2020 May 14.
Recent findings suggest that the colonization of habitat patches may be affected by the quality of surrounding patches. For instance, patches that lack predators may be avoided when located near others with predators, a pattern known as risk contagion. Alternatively, predator avoidance might also redirect dispersal towards nearby predator-free patches resulting in so-called habitat compression. However, it is largely unknown how predators continue to influence these habitat selection behaviours at increasing distances from outside of their own habitat patch. In addition, current information is derived from artificial mesocosm experiments, while support from natural ecosystems is lacking. This study used bromeliad landscapes as a natural model system to study how oviposition habitat selection of Diptera responds to the cues of a distant predator, the carnivorous elephant mosquito larva. We established landscapes containing predator-free bromeliad habitat patches placed at increasing distances from a predator-containing patch, along with replicate control landscapes. These patches were then left to be colonized by ovipositing bromeliad insects. We found that distance to predators modulates habitat selection decisions. Moreover, different dipteran families had different responses suggesting different habitat selection strategies. In some families, predator-free patches at certain distances from the predator patch were avoided, confirming risk contagion. In other families, these patches received higher numbers of colonists providing evidence of predator-induced habitat compression. We confirm that effects of predators in a natural ecosystem can extend beyond the patch in which the predator is present and that the presence or absence of remote predator effects on habitat selection depends on the distance to predators. The notion that perceived habitat quality can depend on conditions in neighbouring patches forces habitat selection studies to adopt a landscape perspective and account for the effects of both present and remote predators when explaining community assembly in metacommunities.
最近的研究结果表明，生境斑块的定殖可能会受到周围斑块质量的影响。例如，当缺乏捕食者的斑块位于有捕食者的斑块附近时，可能会被回避，这种模式被称为风险蔓延。或者，捕食者回避也可能会将扩散重新引导到附近没有捕食者的斑块，从而导致所谓的栖息地压缩。然而，目前还不清楚捕食者如何在远离自身栖息地斑块的地方继续影响这些栖息地选择行为。此外，目前的信息是从人工中尺度实验中得出的，而缺乏来自自然生态系统的支持。本研究利用凤梨科植物景观作为自然模型系统，研究双翅目昆虫的产卵栖息地选择如何对远处捕食者——食虫象鼻虫幼虫的线索做出反应。我们建立了包含无捕食者凤梨科植物栖息地斑块的景观，这些斑块放置在距离有捕食者斑块越来越远的地方，同时还有复制的对照景观。然后，这些斑块被留下让产卵的凤梨科昆虫定殖。我们发现，与捕食者的距离会调节栖息地选择决策。此外，不同的双翅目科对栖息地选择有不同的反应，表明它们有不同的栖息地选择策略。在一些科中，距离捕食者斑块一定距离的无捕食者斑块被回避，证实了风险蔓延。在其他科中，这些斑块接收了更多的殖民者，这表明存在捕食者诱导的栖息地压缩。我们证实，自然生态系统中的捕食者的影响可以超出捕食者所在的斑块范围，并且远程捕食者对栖息地选择的影响的存在或不存在取决于与捕食者的距离。栖息地质量可以取决于相邻斑块条件的观点迫使栖息地选择研究采用景观视角，并在解释集合群落中的群落组装时，考虑到当前和远程捕食者的影响。
