Natal dispersal in monogamous owl monkeys (Aotus azarai) of the Argentinean Chaco

This study offers a detailed description of natal dispersal patterns in owl monkeys (Aotus azarai) and evaluates the extent and characteristics of sex-biased dispersal in this monogamous mammal. Owl monkeys are small, territorial primates that live in socially monogamous groups in the Argentinean Chaco. Between 1997 and 2007 we recorded the disappearance or dispersal of 102 individuals born in 24 social groups. All individuals, both males and females, left their natal group, and they did so when they were between 2.2 and 4.9 years of age. Most dispersal events occurred immediately before or during the birth season and very few of them occurred during the mating season. Males and females did not differ significantly in the timing of dispersal, the age when they dispersed or how far they dispersed. Dispersals during the harsher Fall/Winter season were associated with the eviction of one or both adults in the group. The limited data on the fate of dispersed individuals suggests that natal dispersal is a highly risk event in the life of owl monkeys. The data also provide adequate support for the inbreeding avoidance hypothesis for natal dispersal in this species.