Evidence for the Deflective Function of Eyespots in Wild Junonia evarete Cramer (Lepidoptera, Nymphalidae)

Abstract

Junonia evarete Cramer is a fast-flying butterfly that perches on the ground with wings opened exhibiting four eyespots close to wing borders. These eyespots presumably function either to intimidate predators, like insectivorous birds, or to deflect bird attacks to less vital parts of the body. We assessed the form, frequency, and location of beak marks on the wings of wild butterflies in central Brazil during two not consecutive years. We found that almost 50% of males and 80% of females bore signals of predator attacks (wing tears), most of them consisting of partially or totally V-shaped forms apparently produced by birds. Males were significantly less attacked and showed a lower proportion of attacks on eyespots than females, suggesting they are better to escape bird attacks. In contrast, females were heavily attacked on eyespots. Eyespot tears in females were higher (and significant different) than expected by chance, indicating that birds do attempt to reach the eyespots when striking on these butterflies. Other comparisons involving the proportion of tears directed or not directed to eyespots in males and females are presented and discussed.

Keywords: Beak marks; Cerrado; escaping; intimidation; protective coloration.