Data from: Can differential nutrient extraction explain property variations in a predatory trap?

Predators exhibit flexible foraging to facilitate taking prey that offer important nutrients. Because trap-building predators have limited control over the prey they encounter, differential nutrient extraction and trap architectural flexibility may be used as a means of prey selection. Here, we tested whether differential nutrient extraction induces flexibility in architecture and stickiness of a spider's web by feeding Nephila pilipes live crickets (CC), live flies (FF), dead crickets with the web stimulated by flies (CD) or dead flies with the web stimulated by crickets (FD). Spiders in the CD group consumed less protein per mass of lipid or carbohydrate, and spiders in the FF group consumed less carbohydrates per mass of protein. Spiders from the CD group built stickier webs that used less silk, whereas spiders in the FF group built webs with more radii, greater catching areas and more silk, compared with other treatments. Our results suggest that differential nutrient extraction is a likely explanation for prey-induced spider web architecture and stickiness variations.

捕食者会采取灵活的觅食策略，以获取富含关键营养的猎物。由于结网型捕食者对其所遭遇的猎物缺乏主动调控能力，它们或可通过差异化营养摄取策略与结网结构的灵活性来实现猎物选择。本研究通过为棒络新妇蜘蛛（Nephila pilipes）饲喂活蟋蟀（CC）、活苍蝇（FF）、经蝇类刺激的死蟋蟀（CD）以及经蟋蟀刺激的死苍蝇（FD），探究差异化营养摄取是否会引发蜘蛛网结构与粘性的可塑性变化。结果显示，CD组蜘蛛在单位脂质/碳水化合物质量下摄入的蛋白质更少，而FF组蜘蛛在单位蛋白质质量下摄入的碳水化合物更少。与其他处理组相比，CD组蜘蛛所结蛛网粘性更强且用丝量更低；FF组蜘蛛所结蛛网则拥有更多辐射丝、更大捕猎面积以及更高用丝量。本研究结果表明，差异化营养摄取或是猎物诱导蜘蛛网结构与粘性产生变异的潜在合理解释。