title: Urinary testosterone levels of wild male bonobos (Pan paniscus) in the Lomako Forest, Democratic Republic of Congo.
abstract: We collected urine samples from seven male bonobos (Pan paniscus) in the Eyengo community, Lomako Forest, Democratic Republic of Congo, and assayed them for testosterone (T). T levels averaged 525 pmol/mg Cr in adult males, and 309 pmol/mg Cr in subadult males. We collected hormonal and behavioral data during a period of relative social instability following the recent arrival of two immigrant males. In concordance with predictions derived from the challenge hypothesis [Wingfield et al., American Naturalist 136:829-846, 1990], which relates T to levels of reproductive aggression, the alpha male had the highest circulating levels of T. When we removed the two recent immigrant males from the analysis, there was a significant positive correlation between T levels and dominance rank for the long-term resident males (n=5, P=0.001, r2=0.98). These are the first data on T levels in wild bonobos, and the results suggest that further study of the relationship between T levels and social context in this species could inform current models relating hormones and aggression in wild apes.
authors.affiliation: Department of Anthropology, Harvard University, Cambridge, Massachusetts 02138, USA. marshall@post.harvard.edu
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Marshall
authors.forename: Gottfried
authors.initials: G
authors.lastname: Hohmann
mesh_terms: D000367:Age Factors; D000374:Aggression / Q000502:physiology*; D000818:Animals; D015023:Democratic Republic of the Congo; D008297:Male; D019974:Pan paniscus / Q000652:urine*; D011157:Population Dynamics; D012931:Social Environment; D013739:Testosterone / Q000652:urine*
chemical_list: D013739:Testosterone