grip. When first meeting, these monkeys will smell each other's faces. The titis will also smell their own scent by rubbing their chests on branches - spreading secretions from their sternal gland - before sniffing them. Its possible that this plays a role when marking territory. They have several visual cues which they display when angry or excited. Most notably shaking of their heads and bodies, swaying, looking away from others, or raising and lashing out with their tail. Other cues include barred teeth, a lowered head, closed eyes, protruding lips or an arched back. There have been observations of the coppery titi monkeys using the Psychotria leaf to self-medicate through fur rubbing. This ritual is rare and does not happen often. They do this by chewing on the plant and rubbing it on their abdomen for about five minutes. This behavior can be interpreted as self-medication since the plant is known for being used as a medical herb in traditional medicine, as well as having anti-viral and anti-bacterial properties. Females will show similar behaviors of their bonded pair to same-sex intruders to show a strong relationship. If successful, the intruder will go away, resulting in reproductive success for the monogamous bonded pair. Once there has been an offspring introduced to a couple, the activity budget of these monkeys will change. The mother will feed more and rested less, and the male will feed less and rested more. This is because the females will forage more to feed the baby, and the male would hold the baby more to protect them. Vocalization and communication Coppery titis are highly vocal animals with a complex set of vocalizations and sounds. Coppery titis will vocalize with grunts, screams, whistles and moans. Their most frequent vocalizations are bellows, pumping, and panting, which are the main components of male-female pair duets. These duets are daily performances which occur during or before sunrise near the edge of their territories. Neighboring pairs respond to each other's duets, establishing territorial boundaries. Duets can last up to five minutes, beginning with moaning and ending with honking. For the duration of the duet, males and females will alternate between bellowing calls and panting responses. Between these sequences, the titis will synchronize in a pumping transition. The amount of time spent between synchronized transitions changes over time. Newly paired couples will spend more time between transitions, while older pairs typically show