Brazilian researchers observe greater complexity in forms of predator avoidance, opening up new prospects for studies on evolution of mimicry (left: Heraclides anchisiades; right: Parides anchises)PETER MOONA new survival tactic has been discovered in butterflies, according to a paper published in the journal Neotropical Entomology. The lead authors are Carlos Eduardo Guimaraes Pinheiro, a researcher at the University of Brasilia (UnB), and Andre Lucci Freitas, affiliated with the University of Campinas (UNICAMP) in Sao Paulo State, Brazil.During their evolution, several butterfly species are known to have developed traits such as the ability to release toxins, resulting in an unpleasant taste to scare off birds and other predators. These unpalatable insects also advertise their toxicity by displaying bright colors, as if to warn enemies to stay away.Palatable butterflies have also developed survival tactics under pressure from predation. For example, they are faster. Many also sport multicolored wing patterns that identify them as nimble and hard to capture.Slower palatable butterflies should naturally be priority targets for predators, but they, too, use tricks to survive: one such ploy is escape mimicry, which involves imitating the colors of their unpalatable cousins.In summary, unpalatable butterflies do not need to invest in escape tactics. They are poisonous and can afford to fly more slowly. Palatable butterflies need to be fast and nimble, or alternatively to mimic unpalatable species, to avoid being eaten. However, the new study shows this is not always what happens.Pinheiro, Freitas and colleagues focused on two species in particular: Heraclides anchisiades capys, which is palatable and very nimble, and Parides anchises nephalion, which is unpalatable, slow and highly poisonous.These two species are not close relatives, yet they display very similar colors, despite some differences. The wing patterns of the nimble H. anchisiades closely resemble those of the poisonous P. anchises, an inhabitant of tropical regions in the Americas.Many other species apart from H. anchisiades imitate P. anchises in a classic example of mimicry, whereby a palatable creature looks very much like an unpalatable one and benefits from the resemblance. However, among all the species that mimic P. anchises,H. anchisiades is one of the fastest and also the most widely distributed in the Americas.At first glance, H. anchisiades looks as if it must be highly toxic, given its coloring. It has the best of both worlds as far as defending itself against predators is concerned. A bird that ignores the poisonous pattern and attempts to prey on H. anchisiades will find itself pursuing a nimble butterfly and will probably expend a great deal of energy without obtaining food. By using mimicry to trick its pursuers, this butterfly reduces the probability of being eaten to a minimum and is able to concentrate on activities such as foraging and reproducing.The nimble butterfly mimics the poisonous butterfly, gaining adaptive advantages by associating its speed and agility with a trait known by birds to signify unpalatability, i.e., toxicity, Freitas said.P. anchises, commonly known as the Anchises Cattleheart, is one of the most poisonous butterflies in the tropical Americas. It flies slowly, thereby suggesting that avoiding predators is not a priority.