THE BEHAVIORAL, ASSOCIATIVE, AND SEXUAL EFFECTS ON YOUNG BULL AFRICAN ELEPHANTS IN RESPONSE TO THE REMOVAL OF THE DOMINANT BULL FROM PONGOLA GAME RESERVE, SOUTH AFRICA

Abstract

It has been determined that dominant bulls are social and ecological repositories of information for the younger bulls (Evans & Harris, 2008). Other reserves have learned that without this dominant bull the younger bulls do not learn how to properly interact socially or copulate with females (Slotow & van Dyk, 2001). Instead, they engage in abnormal social behavior such as killing rhinoceros and entering musth, their sexually reproductive period, at too early an age making them pursue females when they are inexperienced (Slotow & van Dyk, 2001). This study looks at a herd whose dominant bull was hunted and therefore removed and how that has affected the younger bulls within the herd. It was expected to see extreme social upheaval among the younger bulls and a strong change in the dominance hierarchy. While there was a change in the dominance hierarchy it was only among males that were very similar in age and the dominant male kept his position, losing no dominance interactions. Every other form of behavior did not see any change after the dominant bulls’ removal. The bulls at Pongola were all given vasectomies as a population control measure except the dominant bull that was too big for the procedure so he was given gonadotropin-releasing hormone (GnRH). This resulted in the dominant bull not going into musth and therefore not attempting to copulate with females or be aggressive toward the younger bulls to keep his dominant position. By doing this, Pongola Game Reserve was unintentionally creating an opportunity for the beta bull to transition into the dominant position while the dominant bull was still present. Using GnRH to help make a smooth transition between dominant bulls in other game reserves looking to remove the dominant bull is a proactive and preemptive management method.