Lichtenstein James L L, Daniel Karis A, Wong Joanna B, Wright Colin M, Doering Grant Navid, Costa-Pereira Raul, Pruitt Jonathan N
Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.
Department of Biology, Wilson College, Chambersburg, PA, 17201, USA.
Oecologia. 2019 Jun;190(2):297-308. doi: 10.1007/s00442-019-04344-w. Epub 2019 Feb 1.
The individual behavioral traits of predators and prey sometimes determine the outcome of their interactions. Here, we examine whether changes to habitat complexity alter the effects of predator and prey behavior on their survival rates. Specifically, we test whether behavioral traits (activity level, boldness, and perch height) measured in predators and prey or multivariate behavioral volumes best predict the survival rates of both trophic levels in staged mesocosms with contrasting structural complexity. Behavioral volumes and hypervolumes are a composite group-level behavioral diversity metric built from the individual-level behavioral traits we measured in predators and prey. We stocked mesocosms with a host plant and groups of cannibalistic predators (n = 5 mantises/mesocosm) and their prey (n = 15 katydids/mesocosm), and mesocosms varied in the presence/absence of additional non-living climbing structures. We found that mantis survival rates were unrelated to any behavioral metric considered here, but were higher in structurally complex mesocosms. Unexpectedly, katydids were more likely to survive when mantis groups occupied larger behavioral volumes, indicating that more behaviorally diverse predator groups are less lethal. Katydid mortality was also increased when both predators and prey exhibited higher average perch heights, but this effect was increased by the addition of supplemental structure. This is consistent with the expectation that structural complexity increases the effect of intraspecific behavioral variation on prey survival rates. Collectively, these results convey that the effects of predator and prey behavior on prey survival could depend highly on the environment in which they are evaluated.
捕食者和猎物的个体行为特征有时会决定它们相互作用的结果。在此，我们研究栖息地复杂性的变化是否会改变捕食者和猎物行为对其存活率的影响。具体而言，我们测试在捕食者和猎物中测量的行为特征（活动水平、大胆程度和栖息高度）或多变量行为量是否最能预测在具有不同结构复杂性的实验中型生态系统中两个营养级的存活率。行为量和超体积是一种综合的群体水平行为多样性指标，由我们在捕食者和猎物中测量的个体水平行为特征构建而成。我们在中型生态系统中投放了一种寄主植物以及自相残杀的捕食者群体（每个中型生态系统中有5只螳螂）和它们的猎物（每个中型生态系统中有15只螽斯），并且中型生态系统根据是否存在额外的非生物攀爬结构而有所不同。我们发现螳螂的存活率与这里考虑的任何行为指标都无关，但在结构复杂的中型生态系统中更高。出乎意料的是，当螳螂群体占据更大的行为量时，螽斯更有可能存活，这表明行为更多样化的捕食者群体杀伤力更小。当捕食者和猎物都表现出更高的平均栖息高度时，螽斯的死亡率也会增加，但补充结构会增强这种影响。这与结构复杂性增加种内行为变异对猎物存活率影响的预期一致。总体而言，这些结果表明捕食者和猎物行为对猎物存活率的影响可能高度依赖于评估它们的环境。
