Abstract # 84:

Scheduled for Saturday, June 21, 2008 03:30 PM-03:40 PM: Session 11 (Meeting Room 2DEF) Oral Presentation

The effect of feeding competition and co-feeding on grooming exchanges among female baboons (Papio anubis)

R. E. Frank
UCLA, Department of Anthropology, 341 Haines Hall Box 951553, Los Angeles, CA 90095-1553, USA
     The observation that female chacma baboons balance grooming within bouts more evenly when rates of aggression are elevated has been interpreted as evidence that females use grooming to pay for tolerance in a biological marketplace. However, the links between females’ diets, feeding aggression, and grooming patterns have not been fully examined. Here, I examine the prediction that feeding competition is linked to rates of co-feeding and the patterning of grooming exchanges among free-ranging female olive baboons (N=16) observed over an 18 month period. Dyads that spent more time co-feeding had the highest rates of feeding conflict [n=1514, Wald c2(1)=39.42, p<0.0001]. While the total amount of feeding conflict that individual females experienced each month did not significantly affect their grooming contributions in bouts with dominant partners [n=149, Wald c2(1)=0.93, p=0.34], elevated feeding conflict within a dyad increased the within bout grooming contribution of the lower ranking partner in that dyad [n=149, Wald c2(3)=19.47, p=0.0002]. However, increased grooming contributions by subordinate partners did not affect the time partners spent co-feeding [n=252, Wald c2(1)=0.01, p=0.92]. Thus, while females may attempt to reduce conflict by grooming dominant partners, it is not clear that they are trading for equal value in a biological market.