Abstract # 6236 Poster # 195:

Scheduled for Friday, June 19, 2015 06:00 PM-08:00 PM: (Cascade AJBCD) Poster Presentation


IS URGENCY ENCODED IN THE TSIK CALLS OF COMMON MARMOSETS?

M. M. Mulholland1,2, M. G. Rice2, K. R. Chudeau2 and N. G. Caine2
1University of Nebraska-Lincoln, Department of Psychology, Lincoln, NE 68588-0308, USA, 2California State University San Marcos
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     Referential alarm calls have been demonstrated in two closely related species of tamarins (Saguinus fuscicollis and S. mystax) and in Geoffroy’s marmosets (Callithrix geoffroyi). However, it is not known if marmosets modulate call production to indicate the urgency of predatory threat. We hypothesized that marmosets would respond with higher rates of tsik calls to a large, rearing rattlesnake model (higher risk) than to a smaller rattlesnake model in a non-rearing position (lower threat). These stimuli were presented to six captive common marmosets (Callithrix jacchus) while individually isolated in a small area of their enclosure. Contrary to our hypothesis, there was no significant difference in the number of tsik calls given to the two models over a one-minute exposure, t(6)=.51, p>.05. However, the marmosets did spend significantly less time at the front of the enclosure (where the models were presented) when exposed to the higher threat model, t(6)=-2.67, p<.05, suggesting that the monkeys did discriminate between the two stimuli. These findings do not support the hypothesis that marmosets alter the rate of production of tsik calls in an urgency-based manner. However, rate may not be the only feature of the calls that signals urgency. Further acoustic analyses need to be performed to determine if the structure of the tsik calls given in high- and low threat conditions are different.