Distractive marks have been suggested to prevent predator detection or recognition of a prey, by drawing
the attention away from recognizable traits of the bearer. The white ‘comma’ on the wings of comma
butterflies, Polygonia c-album, has been suggested to represent such a distractive mark. In a laboratory
experiment using blue tits, Cyanistes caeruleus, as predators, we show that the comma increased survival,
since the blue