Anthropology, Clark College
Friday 211, Plaza Level
Despite differences in body size and social behavior between males and females of many dimorphic primate species, field observations have identified only very subtle intraspecific sex-based differences in primate positional behavior. In this study, I compare positional behavior profiles for male and female Lowe’s guenon (Cercopithecus campbelli lowei) and ursine colobus (Colobus vellerosus) in Ghana’s Boabeng Fiema Monkey Sanctuary (BFMS). Using a 3-minute instantaneous technique, I sampled the behavior of adult individuals of both sexes from guenon and colobus groups at BFMS. I used a G-test (α=0.05) to identify significant associations between sex and defined postural and/or locomotor categories within frequency tables generated for each species. For both species, sex and posture (guenon: p<0.000; colobus: p=0.003) as well as sex and locomotion (guenon: p=0.011; colobus: p=0.034) were significantly associated variables. Using concurrently collected habitat usage data (the location, size and orientation of supports utilized by a focal animal), I argue that male vigilance behaviors, constraints imposed by larger male body size and dietary differences between males and females drive these subtle postural and locomotor differences. However, the overall similarity between sexes in preferred postures or locomotor behaviors suggests that evolutionary history exerts a greater constraint on positional behavior than sex. These subtle intraspecific differences reinforce the finding of other field studies that positional behavior is largely conservative within primate clades.