Meeting Abstract
Tymbalar clicks produced by tiger moths play a role in both natural selection and sexual selection. Some species use clicks to jam bat echolocation and enhance survival. To jam sonar, moth clicks should be produced in a narrow time window, just before the arrival of an echo. One strategy to achieve this time coincidence could be to produce clicks at higher duty cycles (DC). Tiger moth sounds are also involved in the courtship behavior. In most species, males produce sound and females choose among males based on their acoustic signals. Little is known about the critical characteristics of the sound influencing mate choice and the effectiveness of sonar jamming. This study combines behavioral and neurophysiological experiments to evaluate the effect of the DC of moth signals on bat foraging performance and on the moth’s mating success. We recorded the echolocation behavior of big brown bats (Eptesicus fuscus) attacking tethered moths in a flight room, under the effect of Bertholdia trigona signals with different DC (5% – 45%). High DC signals were more effective at deterring bats performance. Neurons from the inferior colliculus of E. fuscus were recorded in response to echolocation calls and B. trigona signals. The temporal pattern of the neural response to the echolocation signals was disrupted in the presence of moth clicks produced at 25% and 45% DC. Female choice experiments during the mating behavior showed that B. trigona males with lower acoustic capabilities (moderate-clickers or silent males) were less successful in mating. These results suggest that both sexual selection and natural selection drive the evolution of high duty cycles and, thereby mold the acoustic repertoire of B. trigona.
