Abstract # 4297 Poster # 45:

Scheduled for Thursday, June 21, 2012 07:00 PM-09:00 PM: Session 9 (Gardenia) Poster Presentation


BEHAVIORAL CHANGES ASSOCIATED WITH SEXUAL STATE IN ZOO-LIVING CHIMPANZEES (PAN TROGLODYTES) AND GORILLAS (GORILLA GORILLA GORILLA)

M. C. Fitzpatrick, K. E. Wagner and S. R. Ross
Lincoln Park Zoo, 2001 North Clark St., Lester E. Fisher Center for the Study and Conservation of Apes, Chicago, IL 60614, USA
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     The influence of sexual state on great ape behavior has been well documented at the dyadic level for the purpose of understanding social relationships. Although these cyclical changes in sexual receptivity may be significant on a broader social scale, little research has examined these changes at a group level. We examined behaviors associated with sexual receptivity in mixed-sex, naturally structured captive groups of chimpanzees (3 males, 4 females; 10-24 years) and gorillas (2 males, 5 females; 6-29 years). Behavioral data were collected using focal observations with 30-scan intervals as part of ongoing monitoring. Chimpanzee receptivity was assigned based on visual assessment of swelling size; gorilla receptivity periods were determined by an oral contraception cycle, which included a placebo pill administered daily to females one week/month. We assigned receptivity scores to each week for 3 years, based on mode swelling level or contraceptive state (high=full swelling or no pill; low= less-than-full swelling or pill) and assessed state-related changes in 7 behavioral categories. During high receptivity periods, chimpanzee subjects showed higher frequencies of abnormal behaviors (F(1,12)=3.051, p=0.049), and lower levels of prosociality (F(1,12)=3.368,p=0.038). Gorilla receptivity was associated with higher frequencies of attention (F(1,12)=6.80, p=0.012), and lower levels of inactivity (F(1,12)=4.39, p=0.041) in group members. These results show significant behavioral variances with sexual state, suggesting that perhaps species-typical patterns of group attention and sociality affect sexual behavior differently.