Meeting Abstract

83.1  Monday, Jan. 6 10:30  Steering sound beams: The influence of social context on acoustic radiation patterns in Neotropical singing mice PASCH, B*; ABBASI, M; PHELPS, SM; WILSON, PS; RYAN, MJ; University of Texas at Austin; University of Texas at Austin; University of Texas at Austin; University of Texas at Austin; University of Texas at Austin bpasch@utexas.edu

The efficacy of animal communication depends upon signal detection by receivers following propagation through an oft-cluttered environment. Most studies of acoustic displays used in sexual contexts focus on the role of spectral and temporal characteristics in signal evolution. However, sound waves generally radiate from a vocalizing animal with unequal amplitude in different directions. This favors adaptations that exploit or compensate for acoustic directionality. In this experiment, we used a hemispheric microphone array in an anechoic chamber to record from male Alston’s singing mice (Scotinomys teguina) before and after playback of a conspecific vocalization. In this species, males commonly emit stereotyped and elaborate vocalizations that serve to repel rival males. Upon hearing conspecific song, males oriented towards the speaker and produced vocalizations that were longer (+1 s), lower in frequency (-1 kHz), and greater in intensity (+ 4 dB), which contributed to changes in acoustic directionality. Our data suggests that males dynamically adjust vocal output and directionality to expand the signals’ active space and advertise aggressive intent.