Abstract # 2831 Event # 122:

Scheduled for Saturday, June 19, 2010 08:45 AM-08:55 AM: Session 20 (Medallion Ballroom B) Oral Presentation


EVIDENCE FOR REFERENTIAL ALARM CALLS IN GEOFFROY'S MARMOSETS (CALLITHRIX GEOFFROYI)

M. M. Petracca, E. Lane and N. G. Caine
CSU San Marcos, Department of Psychology, San Marcos, CA 92096, USA
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The perception criterion of referential communication is met when animals that hear a vocalization behave in a way that is consistent with the context of the call’s production. In the current study we measured the response of ten outdoor living, captive marmosets to playbacks of alarm calls they had given to models of snakes and perched raptors. Binomial tests [α=0.05] confirmed our predictions that the marmosets would look down in response to snake alarm calls and would approach the speaker. Also as predicted, the monkeys did not approach the speaker following raptor alarm calls, and they did tend to look up [70% of trials], but not significantly more than was predicted by chance. Repeated measures ANOVAs and t-tests [α=0.05] did not confirm our predictions that the marmosets would choose to forage under covered platforms after hearing hawk alarm calls, or that they would avoid foraging on the ground after hearing snake alarm calls in the ten minutes following playbacks. Our data suggest that the marmosets’ most immediate reactions to snake and raptor alarm calls probably meet the perception criterion, but alarm calls in the absence of repeated announcement or confirmatory visual evidence of a predator’s presence may be dismissed as a false alarm. This interpretation is consistent with the marmosets’ tendency to reduce the costs of unnecessary vigilance.