Cognitive dimensions of predator responses to imperfect mimicry?

Lars Chittka,Daniel Osorio

doi:10.1038/npre.2007.1258.1

Abstract

AbstractMany palatable insects, for example hoverflies, deter predators by mimicking well-defended insects such as wasps. However, for human observers, these flies often seem to be little better than caricatures of wasps – their visual appearance and behaviour are easily distinguishable. This imperfect mimicry baffles evolutionary biologists, because one might expect natural selection to do a more thorough job. Here we discuss two types of cognitive processes that might explain why mimics distinguishable mimics might enjoy increased protection from predation. Speed accuracy tradeoffs in predator decision making might give imperfect mimics sufficient time to escape, and predators under time constraint might avoid time-consuming discriminations between well-defended models and inaccurate edible mimics, and instead adopt a “safety first” policy of avoiding insects with similar appearance. Categorization of prey types by predators could mean that wholly dissimilar mimics may be protected, provided they share some common property with noxious prey.

Highlights

Mimicry—the phenomenon where organisms converge in appearance on one another, often to warn or deceive predators—provides examples of adaptive evolution so striking that they should convince even staunch sceptics of the principles of evolution
Take many of the familiar hoverflies: their yellow and black stripes might resemble a stinging wasp to an inexperienced observer—but the body shape, flight behaviour, and colour pattern of many species identify them as defenceless flies (Figure 1)
The second prediction is that a predator, under time constraint, will avoid time-costly discriminations between defended models and inaccurate edible mimics, and instead adopt a “safety first” policy of avoiding all insects with similar appearance

Summary

Cognitive dimensions of predator responses to imperfect mimicry

Lars and Osorio, Daniel (2007) Cognitive dimensions of predator responses to imperfect mimicry. ISSN 1544-9173 This version is available from Sussex Research Online: http://sro.sussex.ac.uk/id/eprint/28873/ This document is made available in accordance with publisher policies and may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher’s version. Please see the URL above for details on accessing the published version. Copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way

Cognitive Dimensions of Predator Responses to Imperfect Mimicry?

Introduction

Categorisation of Food Types by Animals

Testing the Role of Prey Categorisation in Insectivores

Conclusion