PLAYBACK STUDIES OF AFFILIATIVE VOCALIZING IN CAPTIVE SQUIRREL-MONKEYS - FAMILIARITY AS A CUE TO RESPONSE

1. A captive social group of squirrel monkeys in an outdoor habitat was presented with recorded chuck calls obtained from conspecific neighbors, neighbors of another Saimiri species, conspecific strangers, and members of the target group itself. 2. Responses to playback of chucks from their own group members were indistinguishable (in frequency, type, and latency) from those made to spontaneously emitted chucks. 3. The most familiar chucks (own group playbacks) received affiliative (chuck) responses as frequently as did spontaneously emitted chucks. Chuck playbacks from neighbors (conspecific or not) and strangers got significantly fewer chuck responses. 4. Chuck playbacks from conspecific neighbors received responses indicating mild interest, those from neighbors of another species received agonistic vocal responses, and those from conspecific strangers received both mild interest and agonism. 5. Own group chucks with multiple repeating elements elicited a higher response rate than single element chucks. This effect did not obtain for playbacks from animals outside the target group. 6. Results suggest that playback techniques can be successful with close range affiliative vocalizations like the chuck and that familiarity, species identity, and acoustic structure are all important variables.