Abstract # 195:

Scheduled for Monday, September 15, 2014 01:00 PM-01:15 PM: Session 27 (Mary Gay) Oral Presentation


S. J. Neal, J. Wombolt, M. Rice and N. Caine
California State University, San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, USA
     Scratching is a reliable indicator of anxiety in many species of primates. However, most studies of scratching in relation to anxiety in callitrichids have taken place in laboratories where testing occurred outside the social group. We investigated scratching in eleven outdoor-housed captive common marmosets (Callithrix jacchus) during three anxiety-inducing conditions: predation threat, brief social isolation, and food competition. We recorded scratching during a 15-minute baseline period, a four- or eight- minute experimental induction of anxiety period, and a 10-minute post-induction period using all-occurrences sampling. Each marmoset served as a subject during three trials in each condition between August 2013 and March 2014. Scratching rates per minute were calculated for analyses. A repeated measures ANOVA revealed that there was a main effect of time period, F (1.75, 148.58) = 9.73, p < .001. Subjects exhibited significantly lower scratching rates during experimental induction of anxiety (M = .13, SE = .03) than during baseline (M = .27, SE = .02) (t (148.58) = -4.16, p < .001), or during the post-induction period (M = .30, SE = .04) (t (148.58) = -3.63, p < .001). These results are inconsistent with previous research showing increases in scratching during these same anxiety-provoking situations. Stressful events may be experienced differently in socially cooperative species like marmosets when they experience those stressors in the context of the social group.