Predicting how the inducible defences of large mammals to human predation shape spatial food web dynamics

一个多世纪以来，探索构成食物网的机制一直是生态学研究的基石。捕食者-猎物相互作用的重要性已经得到强调，特别是在营养系统顶端附近的大型动物之间。捕食者施加消耗性效应(Ces)和非消耗性效应(NCEs)，表现为猎物为避免捕食而做出的危害健康的权衡决定(即NCEs)。这些CE和NCEs的性质和强度可以向下传递营养系统，并推动被捕食诱导的猎物防御系统的进化。从这项研究工作中学到了很多东西，但仍然存在两个重要的知识差距，这两个差距都与食物链顶端的人类捕食有关。首先，目前尚不清楚大型动物是否进化出了由人类捕食诱导的防御系统。这一点尚不清楚，因为大型动物为应对人类捕食而做出的决定所付出的代价还没有得到适当的量化。其次，人类诱导的NCEs对食物网动态的影响尚未被测量。因此，目前尚不清楚人类的捕食行为是否会影响营养系统。我将通过对乌干达大型哺乳动物系统经历人类自给自足偷猎的实验研究来填补生态理解方面的这些主要空白。将我的880平方公里的研究区域分为同等大小的处理部分(自给性偷猎很常见)和对照组(由于距离人类社区的距离，自给性偷猎自然很少)，我将量化大型哺乳动物决策的成本，并建立栖息域模型，以阐明人类捕食如何塑造食物网络动态。虽然众所周知，人类对营养系统有自上而下和自下而上的影响，但我的项目将阐明人类捕食产生的级联机制的方式，对地球上其他所有营养系统都有重要影响。

Exploring the mechanisms that structure food webs has been a cornerstone of ecological inquiry for over a century. The importance of predator-prey interactions, particularly among large animals near the apex positions of trophic systems, has been highlighted. Predators exert consumptive, also known as lethal, effects (CEs), and nonconsumptive effects (NCEs), represented by the fitness-compromising tradeoff decisions that prey make to avoid predation (i.e., NCEs). The nature and strength of these CEs and NCEs can cascade down trophic systems and drive the evolution of defences in prey induced by predation. Much has been learned from this research effort and yet, two vital knowledge gaps persist, both relating to human predation at the top of food chains. First, it is not known whether large animals have evolved defences that are induced by human predation. This is unclear because the costs of large animal decisions in response to human predation have not yet been properly quantified. Second, the impact of human-induced NCEs on food web dynamics has not been measured. Consequently, it is not known whether human predation exerts effects that can cascade down trophic systems. I will fill these major voids in ecological understanding via experimental study of a Ugandan large mammal system experiencing human predation from subsistence poaching. Dividing my 880 km2 study area into equal-sized treatment (where subsistence poaching is common) and control (where subsistence poaching is naturally rare because of distance from human community) portions, I will quantify the costs of large mammal decisions and fit habitat domain models to elucidate how human predation shapes food web dynamics. While it is widely known that humans have top-down and bottom-up impacts on trophic systems, my project will articulate the ways in which cascading mechanisms can flow from human predation with important implications in the Anthropocene for every other trophic system on earth.