Abstract # 2310 Event # 3:

Scheduled for Thursday, June 21, 2007 09:45 AM-10:00 AM: Session 1 (North Main Hall C/D) Oral Presentation

Unrelated Females Housed in Unisexual Groups Interfere in Fights in a Male-like Pattern that is Unassociated with Affiliation and That Tends to Prolong Aggressive Encounters

D. J. Pappano, M. Ayers, D. Cairnes, M. C. May and J. R. Kaplan
Department of Comparative Medicine, Comparative Medicine Clinical Research Center, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1040, USA
     In a typical fight, one monkey threatens or attacks a second. Often such fights dissipate. However, sometimes a third party becomes involved, an event termed “fight interference” or “agonistic aiding”. Studies in free-living and compound dwelling animals indicate that females – in comparison to males – tend to interfere on behalf of victims and relatives and frequently are subordinate to the initial attacker (thus placing themselves at risk). The current study evaluated fight interference patterns over six weeks among 50 unrelated, adult female cynomolgus monkeys (Macaca fascicularis) living in 10 groups of four to six animals each, and housed together for three years. Data from each group were collected during 10, 30 minute sessions in which all grooming, body contact, and fights were recorded. Forty-two episodes of interference occurred in 1661 dyadic fights. Analyses [c2 and Kendall’s tau, a=0.05, two-tailed] showed the attacking animal rather than the victim was aided (41 of 42 episodes). Furthermore, such fights were more likely to continue than end (25 episodes vs. 16). In no instance did an animal interfere against a more dominant individual. Also, there was no significant association between affiliation and interference. In summary, in the absence of relatives and life-long peer relationships, female interference largely resembles that of males – they aid aggressors at low risk to themselves and their actions tend to prolong fights. Support: HL45666, HL79421, and grant from Wake Forest University.