Ús de la deslorelina en un ximpanzé mascle en captivitat per reduir l’agressivitat

Abstract

Chimpanzees (Pan troglodytes) are primates that belong to the family of great apes, known as the Hominidae family. They live in societies formed by males and females, which are structured in complex hierarchies, often patriarchal and monopolized by males. Agonistic behaviors play a crucial role in the hierarchy structure of chimpanzee groups: the stress caused by displays and agonistic behaviors generates affiliative and proximity behaviors among the different members of a group. However, an overly aggressive male can create excessive tension among the other group members. Adolescent male chimpanzees start making themselves noticed with displays from a young age, as this allows them to secure a good position in the hierarchy and benefit themselves or, depending on the situation, displace another individual from their rank. Bongo is a young chimpanzee from the Fundacio Mona who, with the onset of adolescence, began to display these notable demonstrations of strength. However, it reached a point where it was affecting the rest of his group members. Constant displays and aggression started to be noticed by the rest of the Mutamba group, to which Bongo belongs, and the stress was really evident.

Deslorelin is an agonist peptide of the gonadotropin-releasing hormone (GnRH) that controls and stimulates the secretion of hormones involved in fertility. It is administered in the form of an implant to some animals to control their fertility but also to reduce aggression in certain males. Several studies have confirmed its effectiveness in mammals, but there is a lack of research regarding chimpanzees. In this study, an implant of deslorelin was administered to Bongo with the aim of reducing agonistic behaviors and increasing affiliative behaviors with his group mates. Additionally, the influence of the deslorelin implant on Bongo's individual behaviors was studied, particularly to see if it influenced the inactivity and the abnormal behaviors, as adverse effects that could influence his health are not desired. The results have shown that the deslorelin implant has presented significant positive effects on affiliative behaviors. There were no significant differences in inactivity. Abnormal behaviors were only significant during the first month after the implant colocation. Agonistic behaviors increased between 2 and 3 months after the implantation but decreased again afterward