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What makes eyespots intimidating–the importance of pairedness
BACKGROUND: Many butterflies possess striking structures called eyespots on their wings, and several studies have sought to understand the selective forces that have shaped their evolution. Work over the last decade has shown that a major function of eyespots is their ability to reduce predation by...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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BioMed Central
2015
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4374370/ https://www.ncbi.nlm.nih.gov/pubmed/25880640 http://dx.doi.org/10.1186/s12862-015-0307-3 |
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author | Mukherjee, Ritwika Kodandaramaiah, Ullasa |
author_facet | Mukherjee, Ritwika Kodandaramaiah, Ullasa |
author_sort | Mukherjee, Ritwika |
collection | PubMed |
description | BACKGROUND: Many butterflies possess striking structures called eyespots on their wings, and several studies have sought to understand the selective forces that have shaped their evolution. Work over the last decade has shown that a major function of eyespots is their ability to reduce predation by being intimidating to attacking predators. Two competing hypotheses seek to explain the cause of intimidation, one suggesting ‘eye-mimicry’ and the other their ‘conspicuousness’ as the reason. There is an on-going debate about which of these better explains the effectiveness of eyespots against predation. We undertook a series of indoor experiments to understand the relative importance of conspicuousness and eye-mimicry, and therefore how predator perception may have influenced the evolution of eyespots. We conducted choice tests where artificial paper models mimicking Junonia almana butterflies were presented to chickens and their preference of attack recorded. RESULTS: We first established that birds avoided models with a pair of eyespots. However, contrary to previous, outdoor experiments, we found that the total area of eyespots did not affect their effectiveness. Non-eye-like, fan shaped patterns derived from eyespots were found to be just as effective as eye-like circular patterns. Furthermore, we did not find a significant effect of symmetry of patterns, again in discordance with previous work. However, across all experiments, models with a pair of patterns, symmetric or asymmetric, eyelike or non-eye-like, suffered from fewer attacks compared with other models. CONCLUSIONS: The study highlights the importance of pairedness of eyespots, and supports the hypothesis that two is a biologically significant number that is important in prey–predator signalling. We discuss the implications of our results for the understanding of eyespot evolution. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-015-0307-3) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-4374370 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-43743702015-03-27 What makes eyespots intimidating–the importance of pairedness Mukherjee, Ritwika Kodandaramaiah, Ullasa BMC Evol Biol Research Article BACKGROUND: Many butterflies possess striking structures called eyespots on their wings, and several studies have sought to understand the selective forces that have shaped their evolution. Work over the last decade has shown that a major function of eyespots is their ability to reduce predation by being intimidating to attacking predators. Two competing hypotheses seek to explain the cause of intimidation, one suggesting ‘eye-mimicry’ and the other their ‘conspicuousness’ as the reason. There is an on-going debate about which of these better explains the effectiveness of eyespots against predation. We undertook a series of indoor experiments to understand the relative importance of conspicuousness and eye-mimicry, and therefore how predator perception may have influenced the evolution of eyespots. We conducted choice tests where artificial paper models mimicking Junonia almana butterflies were presented to chickens and their preference of attack recorded. RESULTS: We first established that birds avoided models with a pair of eyespots. However, contrary to previous, outdoor experiments, we found that the total area of eyespots did not affect their effectiveness. Non-eye-like, fan shaped patterns derived from eyespots were found to be just as effective as eye-like circular patterns. Furthermore, we did not find a significant effect of symmetry of patterns, again in discordance with previous work. However, across all experiments, models with a pair of patterns, symmetric or asymmetric, eyelike or non-eye-like, suffered from fewer attacks compared with other models. CONCLUSIONS: The study highlights the importance of pairedness of eyespots, and supports the hypothesis that two is a biologically significant number that is important in prey–predator signalling. We discuss the implications of our results for the understanding of eyespot evolution. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-015-0307-3) contains supplementary material, which is available to authorized users. BioMed Central 2015-03-09 /pmc/articles/PMC4374370/ /pubmed/25880640 http://dx.doi.org/10.1186/s12862-015-0307-3 Text en © Mukherjee and Kodandaramaiah; licensee BioMed Central. 2015 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Mukherjee, Ritwika Kodandaramaiah, Ullasa What makes eyespots intimidating–the importance of pairedness |
title | What makes eyespots intimidating–the importance of pairedness |
title_full | What makes eyespots intimidating–the importance of pairedness |
title_fullStr | What makes eyespots intimidating–the importance of pairedness |
title_full_unstemmed | What makes eyespots intimidating–the importance of pairedness |
title_short | What makes eyespots intimidating–the importance of pairedness |
title_sort | what makes eyespots intimidating–the importance of pairedness |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4374370/ https://www.ncbi.nlm.nih.gov/pubmed/25880640 http://dx.doi.org/10.1186/s12862-015-0307-3 |
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