Heterogeneity in predator micro-habitat use and the maintenance of Mullerian mimetic diversity

Authored by Zachariah Gompert, Keith Willmott, Marianne Elias

Date Published: 2011

DOI: 10.1016/j.jtbi.2011.04.024

Sponsors: French National Center for Scientific Research (CNRS) United Kingdom Natural Environment Research Council (NERC) United States National Science Foundation (NSF)

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

Mullerian mimicry, where groups of chemically defended species display a common warning color pattern and thereby share the cost of educating predators, is one of the most striking examples of ecological adaptation. Classic models of Mullerian mimicry predict that all unpalatable species of a similar size and form within a community should converge on a single mimetic pattern, but instead communities of unpalatable species often display a remarkable diversity of mimetic patterns (e.g. neotropical ithomiine butterflies). It has been suggested that this apparent paradox may be explained if different suites of predators and species belonging to different mimicry groups utilize different micro-habitats within the community. We developed a stochastic individual-based model for a community of unpalatable mimetic prey species and their predators to evaluate this hypothesis and to examine the effect of predator heterogeneity on prey micro-habitat use. We found that community-level mimetic diversity was higher in simulations with heterogeneous predator micro-habitat use than in simulations with homogeneous predator micro-habitat use. Regardless of the form of predation, mimicry pattern-based assortative mating caused community-level mimetic diversity to persist. Heterogeneity in predator micro-habitat use led to an increased association between mimicry pattern and prey micro-habitat use relative to homogeneous predator micro-habitat use. This increased association was driven, at least in part, by evolutionary convergence of prey micro-habitat use when predators displayed heterogeneous micro-habitat use. These findings provide a theoretical explanation for an important question in evolutionary biology: how is community-level Mullerian mimetic diversity maintained in the face of selection against rare phenotypes? (C) 2011 Elsevier Ltd. All rights reserved.

Tags

Evolution selection Ecological speciation Heliconius butterflies Warning-color Ithomiine butterflies Cryptic coloration Mimicry complexes Host plants Nymphalidae