White-eared titi commencing activity around sunrise and continuing until sunset. Food availability may influence activity times; if there is an abundance of food in the warmer months when plants are fruiting titi monkeys may start earlier, or if there is a lack of food, titi monkeys may remain at the feeding tree into the evening. The titi monkey usually rests during the middle of the day and has two main feeding periods, in the morning and in the afternoon. It has an increased period of feeding towards the end of the day. In total, the titi monkey is active for an average
Red-bellied titi whenever two from the same social group are by each other. The red-bellied titi has a variety of postures and facial expressions that it uses as visual signals. Swaying the entire body, turning the head sideways and lowering the head to face downward are examples of these signals. Observers have seen that these signals are a response to a disturbance or escape tendencies. Arching of the back is a signal that the red-bellied titi uses to warn that they're about to attack. This signal is associated with hostility, after they arch their backs an attack usually follows. Other signals associated