Abstract # 109:

Scheduled for Tuesday, June 4, 2002 10:15 AM-10:30 AM: Session 12 (Room 16/17, Cox Convention Center) Oral Presentation

The alarm reactions of neighboring groups have long-term effects on marmosets

S. J. Hankerson1,2, K. Short2, K. Bachand2 and N. G. Caine2
1U Maryland, College Park, Department of Biology, University of Maryland, College Park, MD 20742, USA, 2California State University, San Marcos
     Callitrichids probably use multiple sources of information to learn about the existence, location and identity of predators in the immediate vicinity. One such source may be the vocalizations of other groups of primates. Will simply hearing the alarm reactions of another group, without actually seeing the source of the alarm, cause more than a short-term alteration of activity patterns? The subjects for this study were two groups of Geoffroy’s marmosets (Callithrix geoffroyi) housed outside, year-round, off exhibit at the Center for Reproduction of Endangered Species at the San Diego Wild Animal Park. Prior to retirement in the evening one group was presented with a snake model, or one of two control conditions. The other group could not see the predator but could hear the neighboring group’s alarm calls. Data were collected the following morning for 30 minutes after emergence from the sleeping box and again in the evening for 30 minutes prior to retirement. As reported previously, the group that was presented with the snake model altered its use of the enclosure and performed more vigilance checks in the snake condition than in the other two conditions the day after exposure. The group that had no visual contact with the predator also shifted its behavioral patterns in the morning and evening, spending more time engaged in visual monitoring behavior and less time resting and grooming. In addition, the marmosets shifted their habitat usage by spending more time than usual away from the vicinity of their sleeping boxes. We conclude that marmosets are sensitive to the alarm reactions of neighboring groups, and that they use the information they gain to modify their behavior for long periods of time.