Ecologia comportamental de Callithrix jacchus (Primates, Callitrichidae) em ambiente de caatinga

Abstract

Callithrix jacchus is a Neotropical primate, with a high adaptability to different environments, occuring in Atlantic Forest and Caatinga. These primates have an omnivorous diet and a polymorphic vision, with two phenotypes in the population (trichromatic and dichromatic). The Caatinga is a semiarid environment that presents extreme conditions such as high temperature and low rainfall, imposing several challenges to animals. Due to these conditions, plant resources are scarce and available only in certain periods of the year. Nonetheless, insects are available during all year. This study aimed to analyze the behavioral ecology of free-living commom marmosets in a Caatinga environment. First, we investigated the behavioral patterns and feeding ecology of these primates in the rainy and dry season. Later, we compared how colour vision affect insect prey capture between females and males. The study was conduted in the Fazenda Marimbondo, located near to Cabaceiras, Paraíba. During 6 months of study, we observed 19 individuals (5 groups), throught the focal animal sampling method associated with ad libitium method. Additionally, we recorded all the consumed plant items and animal prey captures. We observed a significant difference in the resting time between the two seasons, with an increase of this behavior during the dry season. Insectivorous preys were the most explored item by common marmosets, and alternative plant resources such as cactu’s cladode were also consumed. Overall, within the insect consumption, we observed a significant higher number of captures performed by females and a significant higher number in conspicuous insects captures when lactating females were present. Finally, we found a size-coloration effect in the insect captures performed by males (dichromats). These results suggest that Callithrix jacchus adjust their behavioral patterns and feeding ecology to survive in a semiarid environment. Futhermore, the insects captures appear to be influenced by both lactation and colour vision, suggesting that the polymorphism in our population is maintained by heterozygous advantage.