Abstract # 37:

Scheduled for Thursday, August 17, 2006 02:45 PM-03:00 PM: Session 5 (Regency East #2) Oral Presentation

Social Group Influences on Female Estrus Cycling in Captive Chimpanzees at the Primate Foundation of Arizona (PFA)

E. N. Videan1,2 and J. Fritz1
1Primate Foundation of Arizona, PO Box 20027, Mesa, AZ 85277-0027, USA, 2Arizona State University
     The enactment in 1997 of the National Center for Research Resources (NCRR) breeding moratorium mandated changes in chimpanzee social housing at PFA. The purpose of this study was to examine the effects of different social housing on estrus cycling in 19 female chimpanzees (Pan troglodytes), ranging in age from 8.9 to 31.3 years. Each reproductively mature female was housed for an average of 2.2 years in a mixed-sex group (containing at least one sexually-active male) and an average of 2.3 years in an all-female group. Estrus cycling data, including percent of cycle at peak estrous (maximal swelling) and percent of cycle at complete detumescence were compared between mixed-sex and all-female groups using paired t-tests. The percent of cycle at peak estrus significantly decreased when females were housed without access to males (t=2.406, p=0.027), whereas the percent of cycle at complete detumesence tended to increase (t=-1.846, p=0.081). In addition, comparison between the percent of cycle at peak estrus during the first and second years housed without male access revealed a significant time effect decrease (t=3.219, p=0.005). A similar comparison between the first and second years housed with male access revealed no time effect (t=-0.145, p=0.886). Results reveal that social group composition does affect estrus cycling and has important implications for reproductive management.