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The Association of Intergroup Encounters, Dominance Status, and Fecal Androgen and Glucocorticoid Profiles in Wild Male White‐Faced Capuchins ( Cebus capucinus )
Author(s) -
SCHOOF VALÉRIE A. M.,
JACK KATHARINE M.
Publication year - 2013
Publication title -
american journal of primatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.988
H-Index - 81
eISSN - 1098-2345
pISSN - 0275-2565
DOI - 10.1002/ajp.22089
Subject(s) - biology , dominance (genetics) , androgen , offspring , reproductive success , context (archaeology) , demography , endocrinology , hormone , population , pregnancy , biochemistry , sociology , gene , paleontology , genetics
Androgens play a role in male reproductive competition, frequently via aggression, while glucocorticoids are associated with the stress response. However, the relationships of these hormones with different sources of competition (intra‐ vs. intergroup) and dominance status are highly variable. Here, we consider the fecal androgen (f A ) and glucocorticoid (f GC ) profiles of alpha and subordinate male C ebus capucinus in the context of intergroup competition during a rare period of low intragroup competition (i.e. all females were either pregnant or lactating). Intergroup encounters ( IGE s) are a long‐term reproductive strategy in male white‐faced capuchins, enabling them to assess the composition of neighboring groups. IGE s pose a threat to resident males as these can result in injury or death, loss of dominance rank, group eviction, and group takeovers that are frequently associated with infanticide. From F ebruary to J uly 2007, fecal samples were collected from eight males in three groups of white‐faced capuchins in the S anta R osa S ector of the Á rea de C onservación G uanacaste, C osta R ica. IGE rate was positively associated with both f A and f GC levels, indicating that IGE s are perceived as reproductive challenges by resident males, and may be associated with elevated metabolic costs. Alpha males sire the majority of group offspring and, accordingly, the threat of IGE s to both future (via rank loss or eviction) and current (via infanticide) reproductive success is greater than for subordinate males. Consistent with this observation, alpha males had higher f A and f GC levels than subordinate males. Given that all females were either pregnant or lactating and pronounced overt intragroup competition was absent, we interpret the difference in hormone profiles of alpha and subordinate males as being primarily associated with variation in the perceived threats of IGEs according to dominance status. Future studies should focus on the interaction of intra‐ and intergroup competition by examining hormone levels in the presence of periovulatory females. Am. J. Primatol. 75:107‐115, 2013. © 2012 Wiley Periodicals, Inc.