Abstract # 198:

Scheduled for Saturday, June 23, 2007 11:35 AM-11:50 AM: Session 19 (North Main Hall C/D) Symposium

Perspectives on Cooperative Breeding from Golden Lion Tamarins and Coppery Titi Monkeys

K. L. Bales1, J. M. Dietz2, A. J. Baker3, W. A. Mason1 and S. P. Mendoza1
1University of California, Dept of Psychology and California National Primate Research Center, Davis, CA 95616, USA, 2Dept of Biology, University of Maryland, 3Philadelphia Zoological Garden
     Golden lion tamarins (Leontopithecus rosalia) and coppery titi monkeys (Callicebus cupreus) are both arboreal New World monkeys in which adult males and older offspring carry and share food with infants. While levels of adult male care are high in both species, there are significant differences in the behavior of siblings toward infants. In wild tamarins, the number of surviving infants in a group was positively correlated with the number of helpers, and presence of more alloparents led to reductions in carrying by both mothers and fathers. Adult helpers shared food with infants at rates similar to those of parents. In a preliminary, nine-month study of titi monkeys housed at the California National Primate Research Center, infant carrying was recorded continuously for three one-hour focal observations a week. Alloparents (n=12 siblings in eight family groups) carried from 2% to 26% of total time, with a mean of 10.3 + 2.1%. Only fathers reduced carrying in response to higher availability of alloparents (r(10)=-0.84, p < 0.01). Levels of food-sharing by alloparents are very low in titi monkeys, and mostly consist of food “stealing”. Several lines of evidence suggest that alloparenting in callitrichids and titis may serve different proximate and ultimate functions. This research was supported by NSF, California National Primate Research Center, and the Good Nature Institute.