Estratégias de maximização reprodutiva em fêmeas de macaco-de-cheiro silvestre, Saimiri collinsi, na Amazônia oriental.

Abstract

Many mammals coincide their reproductive activities with factors such as ambient temperature, rainfall and food availability. For example, in primates, the periods of maximum fruit production often coincide with the peak of lactation and weaning. This study investigates the relationship between reproductive phases and the availability of fruit in the habitat of two wild squirrel monkey (Saimiri collinsi) groups in the state of Pará (Brazil), which were followed for 12months (June 2014 to May 2015). During this time, we quantified the occurrence of matings, gestations, births and number of lactating females. We also collected phenological data during the study period. Our results show that reproductive events are highly seasonal in S. collinsi. We found that 89% of births (n=18) took place in December and January, and weaning began in March. The period of weaning and infant foraging independence corresponded to an increase of available ripe fruits. This indicates that the period of infant nutritional independence is optimally timed to coincide with the period of greater food production in this habitat. Our results suggest that the strategy of seasonal breeding in squirrel monkeys does not necessarily reduce the energetic stress on lactating females, but likely improves infant survivorship as they transition into independence.