Associate Professor of Anthropology, Queens College and CUNY Graduate Center
http://www.baboonsonline.com/swedell/

Social Behavior and Reproductive Strategies of Female Hamadryas Baboons (Papio hamadryas hamadryas) in Ethiopia.

My dissertation research focused on the role of female behavior in the social organization of wild hamadryas baboons.  The site for this project was the Filoha outpost of the Awash National Park in Ethiopia, where behavioral observations, including 10-minute scan samples, continuous focal samples, and ad libitum observations, took place over fourteen months between October 1996 and September 1998.  Most aspects of the behavioral ecology, reproductive parameters, and social structure of this population were found to be similar to those of other hamadryas populations.  Patterns of social interaction differed, however, in that the "star-shaped" sociogram previously attributed to hamadryas one-male units did not characterize this population. 

At Filoha, females varied widely in their patterns of association and interaction with all age-sex classes of individuals.  Females interacted socially with other females about as much, on average, as they did with their leader males.  The number of females in a unit was positively correlated with the tendency of its females to interact with other females.  Females who spent social time with other females did so at a relatively equal frequency whether or not their leader male was available for social interaction at the time.  The differentiated female social relationships found in this study, combined with genetic data and evidence from other studies, suggested that levels of relatedness among hamadryas females were higher than had previously been assumed and that pairs of hamadryas females who interacted the most may have done so because they were closely related. 

Results from this study also suggested that, while females may have had preferences for some males over others, and occasionally exercised those preferences, a hamadryas female’s main interest lay in maintaining a strong association with her leader male, who could provide protection for bother herself and her offspring.  Observations of kidnappings by non-leader males and protection of infants by leader males suggested that the behavior of non-leader males toward infants had the potential to lead to injury or death and that the protection of a female’s leader male was critical to infant survival.