Abstract # 136:

Scheduled for Friday, August 18, 2006 03:15 PM-03:30 PM: Session 14 (Regency East #2) Oral Presentation


Grooming Reciprocity Among Female Baboons (Papio anubis anubis) Living in Laikipia, Kenya

R. E. Frank
UCLA Department of Anthropology, 341 Haines Hall - Box 951553, Los Angeles, CA 90095-1553, USA
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     Recent data suggest that primates mainly exchange low-cost commodities, like grooming, over short time scales, frequently alternating roles to minimize the risk of being cheated. Analysis of grooming among 16 wild female baboons (807 focal hours) showed that females alternated roles in 20% - 33% of bouts. Within-bout grooming became more balanced as the definition of a bout became more inclusive. When a pause of more than 10 seconds constituted a new bout, within-bout grooming was not balanced (F(1,46) = 1.33, NS). When the criterion was extended to 2 minutes, grooming was evenly balanced (F(2,55) = 5.81, p = 0.005, R-squared = 0.0847). Grooming was also significantly balanced when summed across all of a dyad’s bouts (F(2,84) = 29.41, p < 0.0001, R-squared = 0.3313). Kin were less likely to reciprocate within bouts than nonkin (b ± SE = -0.342 ± 0.203, p= 0.098), but were more balanced in their across-bout grooming (b ± SE = 17.04 ± 6.597, p= 0.012). The effect of kinship disappeared when the receiver’s infant’s age was considered. Receivers without young infants groomed more equitably (F(3,55) = 11.55, P < 0.0001, R-squared = 0.2297, b ± SE = 0.7135 ± .1644, p< 0.001). These data suggest that the exchange of grooming varied across partners and situations, and that grooming was sometimes exchanged for other commodities, such as access to infants.