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

This article investigates the anti-predator defence strategies of Eudaminae skipper butterflies in a Neotropical locality in Peru, focusing on behavioural (flight speed), mechanical (hindwing tails), and chemical (unpalatability) defences. Using feeding experiments with domestic chicks, morphometric analyses, and phylogenetic regressions, the study reveals a broad range of palatability within and among twelve abundant Eudaminae species, with some species exhibiting significant unpalatability previously undocumented in this group. Contrary to initial predictions, faster-flying butterflies (indicated by higher wing loading) tend to be less palatable, and the presence or length of hindwing tails does not correlate with palatability, suggesting that mechanical and chemical defences can co-occur. Additionally, larger body size is associated with increased unpalatability, while habitat preference (open versus forested environments) does not explain variation in palatability. These findings highlight complex, size-dependent combinations of multiple defence strategies in Eudaminae butterflies, challenging assumptions about trade-offs among behavioural, mechanical, and chemical defences in prey species.