Data from: Specialization and accuracy of host-searching butterflies in complex and simple environments

Populations that have access to a variety of resources are often composed of individuals that specialize on different subsets of resources. Understanding the behavioral mechanisms that drive such individual specialization will help us predict the strength of this specialization across different environments. Here, we explore the idea that individual specialization may be a consequence of constraints on an individual’s ability to process information. Because many environments contain an overwhelming number of resources and associated stimuli, individuals that specialize by focusing on only a subset of these resources may make more accurate decisions than individuals that generalize. Furthermore, we expect individuals in complex environments, where there are more resources and associated stimuli to process, to specialize during their search for resources compared to individuals in simple environments. We tested these predictions by measuring the accuracy and degree of specialization of naïve cabbage white butterflies (Pieris rapae) searching for two target host species (radish and cabbage) in simple (one distractor species) and more complex (four distractor species) environments. Only butterflies that specialized on cabbage were more accurate than butterflies that visited a mixture of both radish and cabbage. Furthermore, naïve butterflies searching for hosts in complex environments did not adopt more specialized foraging strategies than naive butterflies searching for hosts in simple environments. Taken together, these results suggest that the foraging benefits associated with specialization might only apply to certain resources (perhaps those that have readily recognizable cues) and that such specializations can be related to accuracy across multiple environments.

拥有多样可利用资源的种群，通常由专注于不同资源子集的个体构成。阐明驱动此类个体特化行为的潜在机制，有助于我们预测不同环境下特化程度的强弱。本研究探讨了一项假说：个体特化或许是个体信息处理能力受限的结果。由于多数环境中存在海量的资源与相关刺激，仅聚焦于部分资源的特化个体，其决策准确性或高于泛化觅食的个体。此外，相较于简单环境中的个体，复杂环境（需处理更多资源与相关刺激）中的个体在觅食过程中更倾向于表现出特化行为。为验证上述预测，我们开展了如下实验：测量未经历觅食训练的菜粉蝶（Pieris rapae）在两种环境下搜寻两种目标寄主植物（host species，萝卜与甘蓝）时的决策准确性与特化程度——简单环境仅含1种干扰物种（distractor species），复杂环境则包含4种干扰物种。仅以甘蓝为特化觅食对象的菜粉蝶，其决策准确性高于同时取食萝卜与甘蓝的个体。此外，在复杂环境中搜寻寄主的未受训菜粉蝶，并未比简单环境中的同类采取更特化的觅食策略。综合来看，本研究结果表明：与特化觅食相关的收益或许仅适用于特定类别的资源（例如那些带有易识别信号的资源），且此类特化行为的准确性可随环境变化而有所差异。