Abstract # 963 Event # 223:

Scheduled for Thursday, August 18, 2005 10:00 AM-10:15 AM: Session 1 (Parliament Room) Oral Presentation

Playbacks of Food Calls Elicit Increased Foraging and Feeding Among Geoffroy’s Marmosets (Callithrix geoffroyi)

C. D. Kitzmann and N. G. Caine
California State University San Marcos, Department of Psychology, San Marcos, CA 92096, USA
     A vocalization is functionally referential when it communicates information about the external environment. To qualify as functionally referential, vocalizations should meet both production and perception criteria. There is some evidence that callitrichid food calls meet the production criterion, but no one has tested whether listeners respond to food calls in a manner indicating perception of referential information about food. This study assessed the perception of referential information in the food calls of Geoffroy’s marmosets. Subjects were twelve adult marmosets in two family groups, housed outdoors, off-exhibit at the San Diego Wild Animal Park’s Center for Conservation and Research for Endangered Species. We presented subjects with playbacks of conspecific food calls and control vocalizations (twitter calls) and measured subsequent levels of food-related behaviors (i.e., foraging and feeding), using instantaneous scan sampling for twenty minutes after each playback. The frequency of food-related behaviors was compared between food call and control conditions using a dependent samples randomization test. When compared to trials with control playbacks, food call playbacks elicited significantly higher levels of food-related behaviors (P = 0.03). Out of twelve adult marmosets, ten exhibited higher levels of food-related behaviors after food call playbacks than they did after control playbacks. This study is the first to evaluate the perception criterion for marmoset food calls, and results support the notion that such calls are functionally referential.