Abstract # 204:

Scheduled for Monday, September 19, 2011 09:15 AM-09:30 AM: Session 25 (Meeting Room 408) Oral Presentation


K. Lam1, N. Cortez1 and R. Ratnam1,2
1University of Texas at San Antonio, San Antonio, TX 78249, USA, 2Texas Biomedical Research Institute, San Antonio, TX 78227

Common marmosets (Callithrix jacchus) utilize their vocal repertoire for maintaining group cohesion, territory, contact with conspecifics, and localizing callers. A series of antiphonal phee calls are used when marmosets are separated from their group. Prior studies have reported the number of spontaneous phee calls and antiphonal calls, the call-response latency, and auditory marker information encoded in vocalizations. However, these studies focused on the response of single subjects to playback. Here, we focus on naturally-occurring interactions within and between 5 separate rooms of 44 individually caged subjects (23 males and 21 females) housed in the same building. We recorded marmoset vocal interactions using one or more microphones over a span of several months. We observed that rooms with a higher male-to-female ratio exhibited more calling activity than rooms that contained less or no males. Phee calls had 1–4 syllables, and the 1-syllable calls occurred most frequently. Further, we observed a 4:1 ratio of spontaneous phee calls to antiphonal calls, and the antiphonal responses typically occurred with a latency of 0–1 sec. This is contrary to the results of playback experiments where more antiphonal calls than spontaneous calls were observed, and latencies less than one second were excluded from analysis. Neuroethological studies involving free behavior contribute towards our understanding of primate acoustic behavioral interactions, vocal communication, function of the auditory system, and their evolution.