Meeting Abstract
P3.45 Monday, Jan. 6 15:30 Siberian hamster vocalizations during aggressive encounters: Influence of sex and season AMADI, C*; RENDON, N.M; KEESOM, S.M; DEMAS, G.E; HURLEY, L.M; Cornell University; Indiana University; Indiana University; Indiana University; Indiana University ca329@cornell.edu
Social context varies across seasons; thus, communication may also vary. For example, the use of song by male passerine birds changes across season in accordance with reproductive state. Less is known about seasonal variation in mammalian communication, including whether the sexes differ in vocal production. Here, we studied vocal behavior during same-sex agonistic encounters of a seasonal mammal, the Siberian hamster (Phodopus sungorus). Hamsters are an excellent model to study seasonal vocal behavior because they display a suite of physiological and behavioral changes across seasons, including aggression in both sexes, and vocalize during social encounters. We predicted that vocalizations would vary across the seasons and correlate with individual levels of aggression. To test this prediction, we housed male and female hamsters in long “summer” days or short “winter” days and recorded video and audio from 5-minute resident-intruder interactions. Aggression was measured by chases and attacks. We characterized two types of vocalizations: high frequency, narrowband syllables as “ultrasonic vocalizations” (USVs) and audible, broadband syllables as “broadband calls” (BBCs). Both male and female hamsters produced USVs and BBCs across seasons. More BBCs were emitted during encounters between short-day animals, and females produced more BBCs than males. BBCs were related to aggression, both across time and with the intensity of the interaction. Collectively, these findings demonstrate a relationship between a particular call type and aggression, which change seasonally. Characterization of vocal behavior across seasons and between sexes contributes to a greater understanding of context-dependent social behavior.
