Uiterwaal Stella F, Squires Amber J, Grappone Bennett A, Dillard Brian, Castaneda Ariadne, Kim Sora L, DeLong John P
School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, USA.
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.
J Anim Ecol. 2023 Apr;92(4):901-912. doi: 10.1111/1365-2656.13901. Epub 2023 Feb 27.
Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community and environmental conditions, can explain variation in diet composition and IGP. Extensive IGP is likely the primary coexistence mechanism in this community, and other factors to which foraging variation is often attributed do not explain diet composition and IGP here. Rather, IGP increases as prey diversity decreases. Foragers are driven to IGP where resource niches are limited. We highlight the need to examine how drivers of predator-prey interaction strengths translate into foraging in natural systems.
生态位分化和集团内捕食（IGP）可以使生态上相似的物种共存，尽管尚不清楚哪种共存机制在消费者群落中占主导地位。到目前为止，从代谢条形码数据中量化饮食的能力有限，这使得测序数据无法用于确定这些机制的相对重要性。在这里，我们将一种最新的代谢条形码量化方法与稳定同位素分析相结合，以研究狼蛛群落中的饮食组成。我们比较了这些蜘蛛中资源划分和IGP的普遍程度，并测试了影响觅食表现的因素，包括个体身份、形态、猎物群落和环境条件，是否能够解释饮食组成和IGP的变化。广泛的IGP可能是该群落中主要的共存机制，而其他通常被认为导致觅食变化的因素在此并不能解释饮食组成和IGP。相反，随着猎物多样性的降低，IGP增加。在资源生态位有限的情况下，觅食者会转向IGP。我们强调需要研究捕食者 - 猎物相互作用强度的驱动因素如何转化为自然系统中的觅食行为。
