Powell Erin C, Taylor Lisa A
Entomology and Nematology Department, University of Florida, 1881 Natural Area Drive, Gainesville, FL 32611, USA.
School of Biological Sciences, University of Auckland, 3A Symonds St, Auckland Central 1010, New Zealand, and.
Behav Ecol. 2017 May-Jun;28(3):890-898. doi: 10.1093/beheco/arx050. Epub 2017 Apr 1.
Individual foraging specialization describes the phenomenon where conspecifics within a population of generalists exhibit differences in foraging behavior, each specializing on different prey types. Individual specialization is widespread in animals, yet is understudied in invertebrates, despite potential impacts to food web and population dynamics (Hymenoptera: Sphecidae) is an excellent system to examine individual specialization. Females of these mud dauber wasps capture and paralyze spiders which they store in mud nests to provision their offspring. Individuals may make hundreds of prey choices in their short lifespan and fully intact prey items can be easily excavated from their mud nests, where each distinct nest cell represents a discrete foraging bout. Using data collected from a single population of (where all individuals had access to the same resources), we found evidence of strong individual specialization; individuals utilized different resources (with respect to prey taxa, prey ecological guild, and prey size) to provision their nests. The extent of individual specialization differed widely within the population with some females displaying extreme specialization (taking only prey from a single species) while others were generalists (taking prey from up to 6 spider families). We also found evidence of temporal consistency in individual specialization over multiple foraging events. We discuss these findings broadly in the context of search images, responses to changing prey availability, and intraspecific competition pressure.
在一个泛化种群体中，同种个体在觅食行为上表现出差异，各自专门针对不同的猎物类型。个体专业化在动物中广泛存在，但在无脊椎动物中却研究不足，尽管其对食物网和种群动态可能有影响。（膜翅目：泥蜂科）是研究个体专业化的一个极佳系统。这些泥蜂雌性会捕获并麻痹蜘蛛，将其储存在泥巢中以供后代食用。个体在其短暂的生命周期内可能会做出数百次猎物选择，并且可以很容易地从它们的泥巢中挖出完整无损的猎物，每个不同的巢室代表一次离散的觅食过程。利用从一个单一群体（所有个体都能获取相同资源）收集的数据，我们发现了个体强烈专业化的证据；个体利用不同的资源（在猎物分类群、猎物生态类群和猎物大小方面）来为它们的巢穴储备食物。个体专业化程度在群体中差异很大，一些雌性表现出极端专业化（只捕食单一物种的猎物），而另一些则是泛化者（捕食多达6个蜘蛛科的猎物）。我们还发现了个体专业化在多次觅食事件中的时间一致性证据。我们将在搜索图像、对不断变化的猎物可获得性的反应以及种内竞争压力的背景下广泛讨论这些发现。
