Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots.
Proc Biol Sci
; 282(1806): 20150202, 2015 05 07.
Article
em En
| MEDLINE
| ID: mdl-25854889
ABSTRACT
Large conspicuous eyespots on butterfly wings have been shown to deter predators. This has been traditionally explained by mimicry of vertebrate eyes, but recently the classic eye-mimicry hypothesis has been challenged. It is proposed that the conspicuousness of the eyespot, not mimicry, is what causes aversion due to sensory biases, neophobia or sensory overloads. We conducted an experiment to directly test whether the eye-mimicry or the conspicuousness hypothesis better explain eyespot efficacy. We used great tits (Parus major) as model predator, and tested their reaction towards animated images on a computer display. Birds were tested against images of butterflies without eyespots, with natural-looking eyespots, and manipulated spots with the same contrast but reduced resemblance to an eye, as well as images of predators (owls) with and without eyes. We found that mimetic eyespots were as effective as true eyes of owls and more efficient in eliciting an aversive response than modified, less mimetic but equally contrasting eyespots. We conclude that the eye-mimicry hypothesis explains our results better than the conspicuousness hypothesis and is thus likely to be an important mechanism behind the evolution of butterfly eyespots.
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Base de dados:
MEDLINE
Assunto principal:
Percepção Visual
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Asas de Animais
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Borboletas
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Aves Canoras
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Mimetismo Biológico
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article