Evolutionary Ecology

, Volume 13, Issue 2, pp 131–140

Fearful symmetry: pattern size and asymmetry affects aposematic signal efficacy

  • Anders Forsman
  • Sami Merilaita

DOI: 10.1023/A:1006630911975

Cite this article as:
Forsman, A. & Merilaita, S. Evolutionary Ecology (1999) 13: 131. doi:10.1023/A:1006630911975


Aposematic animals use anti-predator defence mechanisms such as distastefulness coupled with distinctive odours, sounds, or colour visual signals to predation from domestic chicks we show that the protective value of such visual warning displays is enhanced by increasing size of the signal pattern elements and decreased by pattern asymmetry. These results provide the first experimental evidence that predation may select for individual symmetry of visual warning displays, and concur with earlier demonstrations that asymmetric signals are more difficult to detect, learn, and remember, compared to symmetric signals. Collectively, our findings suggest that prey species possessing warning coloration should be subjected to selection for large and symmetric pattern elements.

animal colorationaposematismevolutionfluctuating asymmetryperceptionpredation

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Anders Forsman
    • 1
  • Sami Merilaita
    • 2
  1. 1.Department of Engineering and Natural SciencesVäxjö UniversityVäxjöSweden
  2. 2.Department of Animal Ecology, Evolutionary Biology CentreUppsala UniversityUppsalaSweden