They start their day waking before dawn and moving about in the branches of the group’s sleeping tree. One group splits into two sleeping parties each night, huddling together while sleeping. Between 5:30 and 8:30 a.m., they move into the sun, away from the sleeping tree and onto exposed ground, and begin feeding and sunbathing. Their sunbathing posture is distinctive; they sit upright on their haunches, spread-eagle, and rest their forearms on their knees, exposing their undersides to direct sunlight. This behavior is probably linked to thermoregulation as it is often seen following cold nights or during cold mornings. The group moves again around noon and they settle in the shade for a brief rest period. They become active again in the early afternoon, foraging, feeding and traveling until the late afternoon. Depending on the time of year, they may take another rest in the mid-afternoon on particularly hot days. After intensely feeding in the late afternoon, the entire group travels back to the sleeping tree where as a group they remain for the rest of the night, but during which individuals may move about the tree, groom, and interact. Groups typically travel together terrestrially. When one is going about the day individually they spend about a third of the day on the ground and the rest of their time is spent in the mid- or upper-level canopy trees and small bushes.
Border disputes with rival groups occur occasionally, the defense of the group’s home range always falls under the command of the dominant female. Agonistic encounters include staring contests, scent taunts between males, lunging approaches and occasional physical aggression. Conflicts conclude when group members retreat toward the center of their home range.
Michael Madrigali, born in 1985, Santa Barbara, CA.
Lives and works in Chicago.