Abstract # 6097 Event # 155:

Scheduled for Friday, June 19, 2015 03:45 PM-04:00 PM: (Cascade E) Oral Presentation


E. C. Lynch1, A. Di Fiore2 and R. A. Palombit1
1Rutgers, The State University of New Jersey, Department of Anthropology, 131 George Street, New Brunswick, NJ 08901, USA, 2University of Texas, Austin

Although multi-male, multi-female cercopithecine societies are generally typified by promiscuous mating and male dispersal, reproduction is often skewed toward a few males, some of whom remain in the group with their offspring. Thus, fathers can interact with offspring through agonistic support, foraging, and protection from infanticide. This study explores how the development of social bonds among immatures is influenced by fathers. We studied juvenile olive baboons (N=39) in one habituated group (n=111) in Kenya for 18 months. Behavioral data were gathered via 6,800 focal animal samples collected over 1,115 observation hours. Genetic relatedness was determined via noninvasive genotyping. Social bond strength was determined using the composite sociality index (CSI), which evaluates both the dyadic rate of grooming and frequency of proximity. Bonds were stronger among paternal half-sibs whose father was present in the group compared to those whose father was absent (present: N=9, absent: N=41; B=-1.21, p<0.01). Bonds among maternal half-siblings were stronger among those whose fathers were absent from the group than those whose fathers were present (present: N=10, absent: N=31, B=2.4, p<0.001). Finally, the bond strength of these paternal half-sibs was intermediate in strength between those of maternal half-sibs and of unrelated immatures only when shared fathers were present (Chi-square=17.6, p<0.001). These data suggest that not only do fathers facilitate the development of relationships among paternal half-siblings, but also those among maternal half-siblings.