The underwing pattern is highly
cryptic. It is conceivable that the eye pattern is a generalized form of
mimicry. It is known that many small animals hesitate to go near patterns resembling eyes with a light-colored
iris and a large
pupil, which matches the appearance of the eyes of many predators that hunt by sight. According to the
Batesian mimicry theory the pattern on the wings of
Caligo resemble the head of a predator like a
lizard or an
amphibian. It should deter predators while resting, feeding, mating, or emerging from the
pupa. The role of eyespots as antipredator mechanisms has been discussed since the 19th century. Several hypotheses are suggested to explain their occurrence. In some butterflies, particularly
Satyrinae (such as the
gatekeeper butterfly and the
grayling), it has been shown that ocelli (eyespots) serve as a decoy, diverting bird attack away from the vulnerable body, and towards the outer part of the hindwings or the forewing tip. Research by Martin Stevens et al. (2008), however, suggests that eyespots are not a form of mimicry and do not deter predators because they look like eyes. Rather the conspicuous contrast in the patterns on the wings deter predators. In this study, however, the influence of surrounding forms, like the head region of a predator, was not tested. Also the question why animals evolved such complex imitations of other species is left unanswered. == References ==