|LONGITUDINAL VARIABILITY IN AFFILIATIVE MAINTENANCE BEHAVIORS IN CAPTIVE COPPERY TITI MONKEYS|
|Lynea R. Witczak1,2, Shelley A. Blozis1, Karen L. Bales1,2. 1University of California, Davis, Davis, California, United States; 2California National Primate Research Center, Davis, California, United States
The present study investigates causes of change in affiliation over time in monogamous coppery titi monkeys (Plecturocebus cupreus). We hypothesized that affiliation varies at the dyadic level, pregnancy predicts increased affiliation, presence of an infant predicts decreased affiliation, and pairing experience predicts affiliation in subsequent pairings. We conducted pair affiliation scan samples 5x/day for one year for 29 pairs. We used nonlinear mixed-effects effects modeling to test whether dyads varied in their initial affiliation, peak affiliation, and peak affiliation timing. Our results show dyad-level variation across all three random effects (X23=33, P< .001). Pregnancy predicted higher levels of affiliation (B=0.005, SE=0.007, t=7.10, P< .001), whereas the presence of an infant predicted lower levels of affiliation (B=-0.004, SE=0.008, t=-5.05, P< .001). Multiple-group growth curve analyses suggest the mean intercept differs between a male’s first pairing and his second (X211=12.35, P=0.34; CFI=0.953; TLI=0.974; RMSEA=0.11). This study suggests pairing experience predicts initial affiliation while pregnancy and parenting predict variation in affiliation over time.