Social behavior and patterns of testosterone and glucocorticoid levels differ between male chacma and Guinea baboons.
In multi-male, multi-female groups of mammals, males usually compete aggressively over access to females. However, species vary in the intensity of male contest competition, which has been linked to differences in testosterone and glucocorticoid profiles. Chacma (Papio ursinus) and Guinea (P. papio) baboons constitute an intriguing model to examine variation in male competition and male endocrine correlates, because of the differences in their social systems. Chacma baboons live in stable female-bonded groups with linear male dominance hierarchies and a high male mating skew, whereas Guinea baboons live in male-bonded, multi-level societies. We recorded male behavior and assayed testosterone (fT) and glucocorticoid metabolite (fGC) levels from fecal samples in one population of each species. Male chacma baboons were more frequently involved in agonistic interactions, and dominance relationships were more consistent than in Guinea baboons, where we could not detect linear hierarchies. Notably, male chacma baboons were also more aggressive towards females, indicating an overall higher aggressiveness in this species. In contrast, male Guinea baboons showed higher levels of affiliative interactions and spatial tolerance. High-ranking and consorting male chacma baboons showed elevated fGC levels and also tended to show elevated fT levels, but there was no effect of consortship in Guinea baboons. Agonism was not related to hormone levels in either species. Thus, predictors of fT and fGC levels in Guinea baboons seem to differ from chacma baboons. Our results support the view that different social systems create differential selection pressures for male aggression, reflected by different hormone profiles.
Cognitive Ethology Laboratory, German Primate Center (DPZ), Kellnerweg 4, 37077 Göttingen, Germany; Department of Anthropology and Archaeology, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta T2N 1N4, Canada. Electronic address: urs.kalbitzer@ucalgary.ca.
Urs
U
Kalbitzer
Endocrinology Laboratory, German Primate Center (DPZ), Kellnerweg 4, 37077 Göttingen, Germany.
Michael
M
Heistermann
Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
Dorothy
D
Cheney
Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
Robert
R
Seyfarth
Cognitive Ethology Laboratory, German Primate Center (DPZ), Kellnerweg 4, 37077 Göttingen, Germany.
Julia
J
Fischer
D000374:Aggression / Q000502:physiology; D000818:Animals; D005243:Feces / Q000737:chemistry; D005260:Female; D005938:Glucocorticoids / Q000032:analysis / Q000378:metabolism*; D008297:Male; D048531:Papio papio / Q000378:metabolism / Q000502:physiology*; D048549:Papio ursinus / Q000378:metabolism / Q000502:physiology*; D012098:Reproduction / Q000502:physiology; D012919:Social Behavior; D012930:Social Dominance; D013739:Testosterone / Q000032:analysis / Q000378:metabolism*
D005938:Glucocorticoids; D013739:Testosterone
Aggression; Androgen; Competition; Cortisol; Dominance; Hierarchy; Papio; Primate; Stress; Tolerance