Abstract # 1008 Event # 110:

Scheduled for Friday, August 19, 2005 10:15 AM-10:30 AM: Session 8 (Mayfair Room) Oral Presentation

Male replacement in a wild group of equatorial sakis (Pithecia aequatorialis)

D. Hurst1, A. Di Fiore2 and E. Fernandez-Duque3
1Department of Anthropology, SUNY Stony Brook, Stony Brook, NY, USA, 2Center for the Study of Human Origins, Department of Anthropology, New York University, 3Zoological Society of San Diego
     Sakis are one of several New World primates that commonly live in “monogamous” family groups, although observations of multimale-multifemale associations are not uncommon. Data on the social dynamics of wild sakis are rare, and no information is available regarding the turnover of reproductive-aged animals within groups. During a long-term study of one saki group in lowland Ecuador, the original resident male died. Over the subsequent weeks, we observed the process by which a new male entered and established himself in the group. Beginning shortly after the resident’s death, unfamiliar solitary males, as well as members of surrounding family groups, were observed entering the study group’s home range, something that was seldom seen previously. During this time, the resident female only once traveled outside her home range, where she was seen with an unknown male. By three weeks after the resident’s death, one new male had begun ranging regularly with the female and participating with her in joint territory defense. Instances of scent marking and of certain vocal behaviors increased in the weeks following the new male’s entry. Given the influx of animals into this group’s home range following the loss of a reproductive-aged individual, we suggest that at least some reported cases of multimale-multifemale groups in sakis may reflect temporary associations occurring during periods of reproductive turnover. Supported by the L.S.B Leakey and Wenner-Gren Foundations.