Spatial Ecology of Reddish-Brown Cuxiú Monkeys (Chiropotes sagulatus, Pitheciidae) in an Isolated Forest Remnant: Movement Patterns and Edge Effects

Abstract

Habitat loss, and subsequent fragmentation, can increase the amount of forest edge. Primate species vary in their responses to such changes in their habitat. We studied the movement ecology of a group of reddish-brown cuxiú monkeys (Chiropotes sagulatus, Pitheciidae) in a small (13 ha), isolated forest remnant that was <3% of the species’ typical home range in the region. Every 5 min we recorded the group’s latitude and longitude, and the behavior of all individuals in sight. We calculated distance, speed, and trajectory of travel routes, and distance from every location to the nearest forest edge. Using Lidar data, we calculated canopy height. Cuxiús traveled in all cardinal directions, but they turned left more often than right, and they traveled at a faster speed to locations where the monkeys fed than where they did not eat. Although cuxiús used forest from the edge to the interior, they concentrated their movements and activities >30 m from the forest edge. Furthermore, their food sites were located less often near the forest edge, and canopy height of food trees near the forest edge was lower than canopy height of food trees at a greater distance from the edge. Although edge effects impacted the monkeys’ movement, trees >15 m at the forest edge can provide resources. Future research can examine ecological variables in more detail with the movement patterns.