Abstract # 133:

Scheduled for Friday, June 19, 2015 11:15 AM-11:30 AM: (Cascade E) Oral Presentation


A COMPARISON OF PROXIMITY VALUES BETWEEN CHIMPANZEES (PAN TROGLODYTES) IN A STABLE AND UNSTABLE GROUP

L. Case, A. Fultz, L. Cohen and E. Loeser
Chimp Haven, 13600 Chimpanzee Pl, Keithville, LA 71047, USA
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     Captive chimpanzees introduced to larger multi-male groups may develop changes in the male dominance hierarchy over time. These changes may affect how often males associate with each other as a threatened alpha seeks allies to assist him. Proximity data were collected on two multi-male groups to determine differences in proximity scores between a stable group (Ed, n = 14; M=6, F=8, age range 22-54, mean 36.6) and an unstable group (Kasey (n = 14; M=5, F=9, age range 23-52, mean 34.2). Stability of the hierarchy was based on the frequency and severity of wounding of the alpha male (Ed = 0 wounds, Kasey = 9 wounds) in the preceding 3 months. Proximity was defined as being within 1m of another chimpanzee. We expected lower scores in the unstable group due to the alpha male’s attempts to elicit support from more individuals. The proximity values between females (F-F) in Ed’s group were higher than those in Kasey’s group (z = 2.29, p = 0.02) but the values between the males (M-M) did not differ (z = -0.60, p = 0.54). Males in both groups tended to spend more time in proximity to other males than females (z = 1.90, p = 0.06). In this study hierarchical instability may have affected female proximity scores, but not male scores, suggesting that hierarchy changes might also affect female associations.