Bales KL, French JA, McWilliams J, Lake RA, Dietz JM. Effects of social status, age, and season on androgen and cortisol levels in wild male golden lion tamarins (Leontopithecus rosalia).
Horm Behav 2006;
49:88-95. [PMID:
15978593 DOI:
10.1016/j.yhbeh.2005.05.006]
[Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 05/04/2005] [Accepted: 05/05/2005] [Indexed: 11/23/2022]
Abstract
This study examines factors affecting androgen and cortisol levels in wild, male golden lion tamarins (Leontopithecus rosalia). Golden lion tamarins are a cooperatively breeding species in which groups often contain two potentially breeding males. Brothers frequently emigrate together and develop a clear dominance hierarchy, but interactions between them are primarily affiliative. Duos in which the males are not related are less stable. In addition, reproductive skew theory predicts that dominant males will be less likely to share reproduction with related subordinates. As such, we predicted that both androgens and cortisol would be higher in subordinate males unrelated to the dominant male. We also predicted that androgens in breeding males would be higher during the mating season than the birth/infant care season, as per Wingfield's "challenge hypothesis" (1990). Fecal samples were collected from 24 males in 14 social groups and assayed by enzyme immunoassay. Androgen levels were higher in breeding males during the mating season, thus supporting the challenge hypothesis. However, while subordinate males unrelated to the dominant male had significantly lower androgens than any other group, cortisol levels were not correspondingly higher. These results suggest that unrelated subordinate males show measurable reproductive suppression and may use strategies such as infantilization to avert aggression from dominant males.
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