Career or Family?: Maternal style and status-seeking behavior in captive bonobos (Pan paniscus).
Department of Biological Anthropology & Anatomy
This is the first study to show a trade-off between primate maternal style and status-seeking behavior. Maternal styles in non-human primates fall along two orthogonal dimensions: protectiveness and rejection, with protectiveness positively correlated with approaching, restraining, grooming and contact-making the infant and rejection positively correlated with breaking contact, leaving and rejecting the infant. These personality styles are comparable to styles identified in research on human psychology. Maternal behavior and status-seeking activities are not mutually exclusive and status-seeking mothers provide direct benefits to their offspring through intergenerational transfer of rank. High-ranking bonobo females have the highest frequencies of social grooming and grooming competition is positively correlated with dominance rank as well as with rank-related competition among lower ranking individuals. This study investigated two dominant bonobo females with nursing infants of the same age at separate captive facilities. A previous study at one of the facilities (Johnson 2007) determined that alliance formation among females was reduced as the result of matrilineal housing that included three full sisters. It was predicted that a more protective maternal style would be observed due to the reduced activity budget devoted to rank-related social grooming. 60 hours of video footage was analyzed detailing all mother-infant interactions and all social grooming bouts at each facility. The matrineally-housed mother showed significantly higher levels of protective infant care while the second mother demonstrated significantly higher levels of grooming time with conspecifics. This suggests that maternal style and status-seeking behavior involves shifting strategies for maximizing female fitness that are context-dependent.
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