Abstract # 16:

Scheduled for Thursday, June 21, 2007 11:15 AM-11:30 AM: Session 3 (North Main Hall F/G) Symposium

Plasticity, Development, and the Social Environment: Vocal Communication in the Marmoset

M. Rukstalis
University of Nebraska at Omaha, Callitrichid Primate Research Center, Department of Psychology, Omaha, NE 68182, USA
     Until the ground breaking work of dedicated primatologists, like Dr. Charles Snowdon, traditional views suggested that nonhuman primate communication was a fixed and invariant process. Dr. Snowdon’s innovative work with callitrichid primates demonstrated that communication is extensively influenced and shaped by the social environment. Inspired by his work, I investigated the ontogeny, social plasticity and communication of identity and social relationships associated with the marmoset phee call. My results suggest that although marmoset infants possess individually specific phee calls as early as two days of age, these vocalizations undergo a significant amount of structural change across early life. A predictive discriminant function analysis could not identify callers at 30 days of age from the structure of their vocalizations recorded just one month earlier (Rukstalis, in preparation). Further, marmosets maintain this plasticity well into adulthood, significantly altering phee call structure in response to changing social environments (Rukstalis et al., 2003). Finally, phee calls, which convey information about identity and social relationships, may also influence physiological functioning. Marmosets isolated in novel environments exhibit significantly elevated levels of urinary cortisol. However, exposure to the phee call of a long-term pair mate leads to significant reductions in cortisol excretion (Rukstalis & French, 2005). Like Dr. Snowdon’s earlier work, these results support the view that communication is a dynamic process inextricably linked and affected by the social environment of primates.