Meeting Abstract

9.1  Tuesday, Jan. 4  Aerial predation in dragonflies: Environmental and mechanical determinants of a complex flight behavior COMBES, S.A.*; CRALL, J.D.; RUNDLE, D.E.; IWASAKI, J.M.; HOLT, K.C.; Harvard University; Harvard University; Harvard University; Harvard University; Harvard University scombes@oeb.harvard.edu

Dragonfly aerial predation is a highly complex, three-dimensional flight behavior that is critical to fitness, yet the variability and mechanics of these acrobatic feats are not well understood. We quantified the predation success of spangled skimmers (Libellula cyanea) pursuing fruitflies (Drosophila melanogaster) in an enclosed, outdoor dragonfly habitat. Over 3000 controlled predation trials were conducted on nine individuals by releasing fruitflies in front of perched dragonflies. Predation success rates were determined for each individual on multiple days (5-18 days per individual). Our data reveal that spangled skimmers are highly efficient predators, with an average success rate of 92.1% (+/- 0.07%). Predation performance is surprisingly consistent among individuals: variability in success rates is higher within individuals (e.g. on different days) than between individuals. To discover the source of this temporal variability, we examined the influence of time of day, temperature, and UV and visual light intensity on predation success. We also captured over 400 high-speed videos of aerial predation events and reconstructed 3-d trajectories to determine how flight biomechanics contributes to the variability observed in capture success. Our results demonstrate the importance of considering both environmental and behavioral variability in understanding the biomechanics of complex flight behaviors.