1Anthropology, University of Pennsylvania, 2Fundación E.C.O., Formosa, Argentina
Saturday All day, Park Concourse
Azara’s owl monkeys (Aotus azarae) are small territorial primates that typically live in socially-monogamous groups of 2 to 6 individuals. In an owl monkey population inhabiting the gallery forest of the Gran Chaco in Formosa, Argentina both male and female offspring disperse from their natal groups and become solitary floaters for a period that ranges from a few days to months. Since solitary floaters often gain reproductive status by displacing reproductive adults in existing groups, examining their ranging patterns is essential for understanding dispersal, territoriality, and adult replacement, which, thus far have only been studied from the perspective of the groups. To this end, we collected daytime ranging data every 20 minutes between dawn and dusk from 11 solitary floaters and we estimated nighttime ranging distance from the locations of floaters at dusk and the following dawn. Floaters ranged farther during full moon nights than during new moon nights, while the reverse pattern was observed for daytime ranging. The activity patterns of floaters were similar to patterns previously described for groups, suggesting that solitary individuals do not significantly alter their activity patterns after dispersing from groups. Although the areas used by solitary floaters overlapped with group territories, the locations of floaters were concentrated on the peripheries of territories, suggesting that floaters alter their ranging behavior, possibly to avoid competition or confrontation with groups.