
Meeting Abstract
Multimodal signaling is common in communication systems. Depending on the species, individual signal components may be produced synchronously as a result of physiological constraint (fixed) or each component may be produced independently (fluid) in time. For animals that rely on fixed signals, a basic prediction is that asynchrony between the components would degrade the signal, reducing receiver response. Male túngara frogs, Physalaemus pustulosus, produce a fixed multisensory courtship signal by vocalizing (whine + chuck call) and inflating a vocal sac. Using a robotic frog, we tested female preferences for variation in the temporal arrangement between acoustic and visual components. When the visual component lagged the call, females largely rejected the multisensory signal. However, this rejection of the asynchronous multisensory signal only occurred when the visual cue followed a full whine-chuck call. When the chuck component was removed, females reversed preference and responded positively to the asynchronous multisensory signal. These data show that asynchrony of a normally fixed signal does reduce receiver responsiveness. The magnitude and overall response, however, depend on specific temporal interactions between the acoustic and visual components. This suggests that female frogs express a degree of plasticity for temporal variation in male signals.