EPOW - Ecology Picture of the Week

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Owl Butterfly's Evil Eye

Credit & Copyright: Dr. Bruce G. Marcot

Explanation:  This butterfly has an evil eye!  Actually, many insects and other animals have false eye spots.  But this Owl Butterfly is well named for its apparent owlish stare created by wing coloration, while the actual eyes go relatively unnoticed.   Of course, such eye spots are well known to help thwart predators ... in this case, probably small birds that themselves avoid being eaten by owls.  Compare the butterfly's eyespot to the various owl eyes shown here at right (from top to bottom, these are Little Owl, Burrowing Owl, Great Horned Owl, and Western Screech-owl). This is an excellent example of classical Batesian mimicry (named for Henry Walter Bates, a 19th-century ecologist and explorer of the Amazon) ... in which a relatively harmless organism's anatomy or behavior mimics that of a harmful species, the model.  The mimic benefits by avoiding predation.  (And even people can use this behavior to frighten away unwanted birds from human habitations.) However, don't jump to conclusions.  Some smaller eye spots may actually induce pecking behavior in some birds.  And some apparent eye spots in other organisms, such as some fish, may aid intraspecific signaling and have nothing to do with thwarting predators.  So ... "an eye for an eye" may not necessarily pertain to all eyespots equally.  Some eyes are more evil than others!