Reduced palatability, fast flight, and tails: Decoding the defence arsenal of Eudaminae skipper butterflies in a Neotropical locality

Abstract

Prey often relies on multiple defences to avoid predators, such as difficulty of capture, attack deflection, or unpleasant taste. Eudaminae skipper butterflies rely on behavioural (fast flight) and mechanical defences (hindwing tails), but other defences like unpalatability (consumption deterrence), and the interaction among defences, have not been assessed.We test the palatability of 12 abundant Eudaminae species from a Neotropical locality, using training and feeding experiments with domestic chicks. Further, we approximate the difficulty of capture explained by flight speed and quantified by wing loading. To test how multiple defences are associated and explained by body size and habitat preference, we perform phylogenetic Bayesian regression analyses.We found a broad range of palatability in Eudaminae, within and among species. Palatability was negatively correlated with wing loading, indicating that butterflies with higher flight speed tend to have lower palatability.The presence or absence of tails did not explain the level of butterfly palatability, showing that attack deflection and consumption deterrence are not mutually exclusive defences. Habitat preference (open or forested environments) did not explain the level of palatability in Eudaminae, but it seems that butterflies with high wing loading (fast flight) tended to occupy semi-closed (e.g., hilltops) or closed habitats (e.g., secondary forest).Finally, the level of unpalatability in Eudaminae is size dependent, larger butterflies are less palatable, perhaps due to their more likely detectability/preference by predators. Altogether, our findings shed light on the contexts favouring the prevalence of single vs. multiple defensive strategies in prey.