Laboratory simulations of mate-guarding as a component of the pair-bond in male titi monkeys, Callicebus cupreus

© 2016 Wiley Periodicals, Inc. Mate-guarding and territorial aggression (both intra- and inter-sexual) are behavioral components of social monogamy seen in male coppery titi monkeys (Callicebus cupreus) both in the field and in the laboratory. Methodology for studying these behaviors in captivity facilitates the translation of questions between field and laboratory. In this study, we tested whether exposure to a mirror would stimulate mate-guarding behavior in male titi monkeys, and whether this exposure was accompanied by hormonal changes. Eight males were exposed to a mirror condition (treatment) or the back of the mirror (control) for five sessions, and behavioral responses were filmed. Blood samples were taken to measure levels of cortisol, oxytocin, and vasopressin. Lipsmacks (P