title: Life at the top: rank and stress in wild male baboons.
abstract: In social hierarchies, dominant individuals experience reproductive and health benefits, but the costs of social dominance remain a topic of debate. Prevailing hypotheses predict that higher-ranking males experience higher testosterone and glucocorticoid (stress hormone) levels than lower-ranking males when hierarchies are unstable but not otherwise. In this long-term study of rank-related stress in a natural population of savannah baboons (Papio cynocephalus), high-ranking males had higher testosterone and lower glucocorticoid levels than other males, regardless of hierarchy stability. The singular exception was for the highest-ranking (alpha) males, who exhibited both high testosterone and high glucocorticoid levels. In particular, alpha males exhibited much higher stress hormone levels than second-ranking (beta) males, suggesting that being at the very top may be more costly than previously thought.
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. lgesquie@princeton.edu
authors.forename: Laurence R
authors.initials: LR
authors.lastname: Gesquiere
authors.forename: Niki H
authors.initials: NH
authors.lastname: Learn
authors.forename: M Carolina M
authors.initials: MC
authors.lastname: Simao
authors.forename: Patrick O
authors.initials: PO
authors.lastname: Onyango
authors.forename: Susan C
authors.initials: SC
authors.lastname: Alberts
authors.forename: Jeanne
authors.initials: J
authors.lastname: Altmann
mesh_terms: D000374:Aggression; D000818:Animals; D001522:Behavior, Animal; D004291:Dominance-Subordination; D005243:Feces / Q000737:chemistry; D005260:Female; D005938:Glucocorticoids / Q000032:analysis; D006608:Hierarchy, Social; D007630:Kenya; D008297:Male; D048548:Papio cynocephalus / Q000502:physiology* / Q000523:psychology*; D012726:Sexual Behavior, Animal; D012930:Social Dominance; D013315:Stress, Psychological; D013739:Testosterone / Q000032:analysis
chemical_list: D005938:Glucocorticoids; D013739:Testosterone