Constant eyespot display as a primary defense – survival of male and female emperor moths when attacked by blue tits

• Large conspicuous eyespots, commonly found on the wings of butterflies and moths, have been shown to thwart attacks from predators. Previous experiments have focused on lepidopteran species that expose eyespots only when harassed by a predator. In contrast, we investigate the potential efficiency of the constantly exposed eyespots of emperor moths thus constituting a primary defense. We staged experiments between blue tits and moths having either intact or painted over eyespots. Moths with eyespots were killed as often as moths without eyespots and were, additionally, approached earlier by the birds suggesting that birds were not intimidated by their eyespots. Female moths weighed three times more than males and were less often eaten, suggesting that their large size intimidated the birds. We suggest that the constant eyespot display of the emperor moth may be associated with a cost, because potential predators seem to be attracted rather than intimidated by the display.

Keyword

Eyespots

predation

anti-predator behavior

emperor moth

Publication and Content Type

ref (subject category)

art (subject category)