28 February 2014

A European Peacock butterfly flashes its eyespots

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This is its defense mechanism to scare off potential predators.
The Peacock butterfly’s main anti-predator defense mechanism comes from the four large eyespots that it has on its wings. These eyespots are brilliantly colored concentric circles. Like many other butterflies that hibernate, the Peacock butterfly exhibits many lines of defense against would-be predators. Avian predators of the butterfly include blue tits, pied flycatchers and other small passerine birds. The first line of defense against these predators for many hibernating butterflies is crypsis, a process in which the butterflies blend into their environment by mimicking a leaf and staying immobile. Some hibernating butterflies such as the Peacock have a second line of defense: when attacked, they open their wings, expose their eyespots and perform an intimidating display of threat. The intimidating visual display shown by the Peacock butterfly gives it a much better chance at escaping predators than butterflies that rely solely on leaf mimicry. While the main targets of these anti-predation measures are small passerine birds, even larger birds such as chickens have been shown to react to the stimuli and avoid the butterfly when exposed to eyespots.
Via A London Salmagundi.

3 comments:

  1. If eyespots work on animals, why shouldn't we put eyespots on the bottom of surfboards and on the back of wetsuits? Sharks almost only attack from the back.

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  2. It puzzles me that the birds that would normally eat butterflies haven't evolved the intelligence, after all these thousands of generations, to know that the "eyes" on the wings of these butterflies aren't part of a larger predator (one with claws that meows, perhaps)? Some of these predatory bird species are smart enough to recognise their spouse from within a large group of maybe thousands of - to us, identical - birds of the same species, like gannets on the sides of cliffs. So why does this eyespot trick still work? Any clues?

    Just thinking about the Professor's idea about eyespots on surfboards and wetsuits, it's possible that our little eyes, being at the front and usually above the waterline, don't work as a deterrent if a shark has tasted us already or is hungry and tempted. If we put big eye spots on the back, wouldn't they just circle around to our front? A safer alternative might be to admit that putting yourself into a shark's world is inherently dangerous and should be avoided by taking up another sport...

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