Abstract # 8:

Scheduled for Thursday, August 18, 2005 11:15 AM-11:30 AM: Session 1 (Parliament Room) Oral Presentation

Vocalizations given during mobbing by captive-reared cotton-top tamarins, Saguinus oedipus

M. W. Campbell and C. T. Snowdon
University of Wisconsin-Madison, Brogden Hall, 1202 W. Johnson St., Madison, WI 53706, USA
     Mobbing is an important component of anti-predator behavior for many species of primates. The small-bodied callitrichid monkeys are believed to suffer a higher predation pressure from a greater variety of predators than other neotropical monkeys. Field observations report callitrichids mobbing predators of multiple types (mammals, reptiles, and perched raptors). The anecdotal nature of these observations has prevented the gathering of quantifiable data, especially in the realm of vocalizations. We tape-recorded mobbing and control (i.e., no stimulus) sessions from 5 families of captive-reared cotton-top tamarins. Vocalizations were identified, measured, and counted via sonogram. We discovered 3 vocalizations that had not been described in the published repertoire for the cotton-top tamarin. Two of these calls, the bark and the growl, are important because they 1) corresponded to the highest intensity of the observed mobbing response, 2) have not been described in detail for any callitrichid, and 3) were never given during control sessions. T-tests confirmed that these high intensity barks and growls were given significantly more often in mobbing sessions than control sessions, and more at the beginning of a session than the end. These new vocalizations are more consistent with hypotheses of mobbing call structure than previous vocalizations. Our results have important implications for understanding anti-predator behavior in wild callitrichids, and for comparing the behavior of captive-born and wild-born subjects. Supported by MH29775, APA, and ABS.