Abstract # 142:

Scheduled for Sunday, September 20, 2009 06:30 PM-09:00 PM: Session 14 (Mission Bay Ballroom CDE) Poster Presentation


RANK-BASED DIFFERENCES IN FECAL ANDROGEN AND CORTISOL LEVELS IN MALE WHITE-FACED CAPUCHINS, CEBUS CAPUCINUS, IN THE SANTA ROSA SECTOR, AREA DE CONSERVACÍON GUANACASTE, COSTA RICA

V. A. Schoof and K. M. Jack
Tulane University, Department of Anthropology, 7041 Freret Street, New Orleans, LA 70118, USA
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In white-faced capuchins (Cebus capucinus), alpha and subordinate males can be easily distinguished; alpha males are often the largest, the most vigilant, and frequently the center of attention. Here we examine if male capuchins also display rank-based differences in their hormonal profiles. Between February and July 2007, we collected 193 fecal samples from all adult [n=7] and subadult [n=1] males [17-27 samples per male] residing in three groups (GN, LV and EX) in the Santa Rosa Sector, Area de Conservacíon Guanacaste, Costa Rica. Each group contained a clear alpha male and one or two subordinate males. When examined as a group, alpha males had higher mean androgen levels [n=3, µ=849.9 ng/g] than subordinate males [n=5, µ=142.3 ng/g; Mann Whitney U test, p=0.036]; this was also true when parsed by group [Mann Whitney U test, pGN=0.001, pLV=0.001, pEX=0.045]. Alpha males as a group do not have higher mean cortisol levels [n=3, µ=102.1 ng/g] than subordinate males [n=5, µ=58.1 ng/g]. However, when examined by group, the alpha males residing with multiple subordinate males had higher cortisol levels than their subordinates [Mann Whitney U test, pGN=0.001, pLV=0.001], but this was not the case for the alpha male residing with a single subordinate [Mann Whitney U test, pEX=0.461]. These data suggest that dominance rank influences the hormone profiles of male white-faced capuchins, though other factors are also likely involved.