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

摘要

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 with individuals in simple environments. We tested these predictions by measuring the accuracy and degree of specialization of na & ve cabbage white butterflies (Pieris rapae) searching for 2 target host species (radish and cabbage) in simple (1 distractor species) and more complex (4 distractor species) environments. Only butterflies that specialized on cabbage were more accurate than butterflies that visited a mixture of both radish and cabbage. Furthermore, na & ve 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.