Densidad, tamaño y composición de grupos de monos congo (Alouatta palliata) y cara blanca (Cebus imitator) en bosque seco y áreas de dosel reducido de Costa Rica

Abstract

Introduction: The size, density and composition of primate social groups are essential for understanding group dynamics and important for determining population management plans for primate conservation. Objective: to determine the size, density and composition of howler monkeys (Alouatta palliata) and white-faced monkey (Cebus imitator) groups in dry forest environments and areas of reduced canopy in Palo Verde National Park. Methods: Field sampling was carried out during the month of February 2023 during the peak hours of primate activity (6:00 a.m. - 12:00 a.m. and 2:00 p.m. - 6:00 p.m.). The individuals of both primate species were counted, recognizing the groups found in both types of environments (dry forest and reduced canopy areas). Results: Howler monkey group sizes were significantly larger in dry forests and at a higher percent of canopy cover. Our analyses show that group size in this primate species depends on the type of environment. Conclusion: greater availability of resources (abundance of food and shelter sites) in closed environments favors the presence of a greater number of individuals of howler monkeys. As for white-faced monkeys, a higher density was recorded in dry forests compared to the last census in 1987. This study highlights the importance of long-term monitoring and studies of these parameters in wild primate groups.