Flight is a vital component of butterfly natural history, and flight-associated morphology is thought to be under strong selection for the performance of critical behaviors such as patrolling, courtship and oviposition. However, while different behaviors require different proportions of flapping versus gliding flight, few studies actually quantify butterfly flight behavior. Moreover, as butterfly flight is anteromotoric, no prior study has measured the role of hind wing allometry in flight. Using high-speed videography, this study compares the flight of two species of Haeterini (Nymphalidae) that regularly employ gliding flight. We also employ stereo videography and experimental hind wing area reduction to measure the effects of hind wing allometry on flight. Results suggest that although the forewings are reliable predictors of flight in these two species, relative hind wing area can significantly affect gliding flight performance, and should be considered as a factor in future investigations on flight-associated morphology in butterflies.

Documenting life history characteristics of populations, especially of herbivorous insects such as butterflies, is fundamental to the ecological study of tropical rainforests. However, we know relatively little about tropical forest butterflies. Here, I combine information gathered using the mark-release-recapture (MRR) approach with manipulative and observational experiments in a natural environment to explore aspects of the population biology of three closely-related species of Costa Rican fruit-feeding understory butterflies (Cithaerias pireta, Dulcedo polita, and Pierella helvina), specifically: vertical stratification, attraction to and persistence in fruit-baited traps, relative abundance and distribution, movement patterns, probabilities of recapture and daily survival, and factors that affect those probabilities. Among the three focal species there were differences in capturability, recapturability, spatial distribution, and degree of vertical stratification. Males appear to fly within smaller home ranges than females, and P. helvina can traverse the entire forest reserve in a single day. These findings have implications for the genetic diversity of these populations and for the risk of local extinction in the face of changing ecological conditions.