Abstract # 2535 Event # 204:

Scheduled for Monday, September 21, 2009 11:15 AM-11:25 AM: Session 20 (Del Mar Room) Oral Presentation


REVERSAL OF FORTUNE: A STUDY OF THE DOMINANCE HIERARCHY IN A CAPTIVE TROOP OF MANDRILLS (MANDRILLUS SPHINX)

M. K. Brown and K. E. Jaffe
Sonoma State University, Dept. of Anthropology and Linguistics, Rohnert Park, CA 94928, USA
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Recent research on wild mandrills suggests they live in very large, multi-male/multi-female troops (Abernethy, et al., 2002) which differs greatly from captivity, where a single male and a few females are housed together year-round. We conducted a year-long study of one mandrill troop (four females and one male) housed at the San Francisco Zoo. During the study period, one female (SLK) was allowed to cycle while the others were restricted. Our goal was to determine if the dominance hierarchy was impacted. Seventy hours of data were collected, using continuous recording and behavioral sampling, focusing on dominance interactions including supplants, ties and reversals. In Phase 1, a stable dominance hierarchy was documented (M>RGY>JNR>SLK>FTY [Matman 1.1]). As the most dominant female (RGY) exhibited poor health (Phase 2) and then, as SLK exhibited perineal swelling (Phase 3), the number of ties and reversals increased significantly from 1.6/hr during Phase 1 to 10/hr during Phase 3 [Friedman's test: Χ2(2)=7.13, p=0.028]. Additionally, in Phase 3, as the hierarchy destabilized, RGY and JNR dropped one rank each while the fertile female, SLK, rose two ranks (M>SLK>RGY>JNR>FTY). However, despite SLK’s ascendency and sexual swelling, the male continued to show little interest in her. The results of this study will be of interest to primatologists as it provides important information for captive mandrill breeding programs.