Behaviour 2019
Searching for inbreeding avoidance behaviors in a small, closed population of African elephants
Katie F. Gough1,2, Adrian M. Shrader1,3, Graham I.H. Kerley1. 1Nelson Mandela University, Port Elizabeth, , South Africa; 2University College Dublin, Dublin, , Ireland; 3University of Pretoria, Pretoria, , South Africa

African elephants use a combination of inbreeding avoidance (IA) mechanisms: sex-biased dispersal and avoidance of mating with close relatives. The substantial increase in the number of small, fenced elephant populations in South Africa, effectively negates male dispersal as an IA mechanism. We examined the association patterns of adult male and female elephants in a range restricted population for behavioral IA mechanisms. Data were collected on the Addo Elephant National Park population (104 females, 44 males), where maternal lineage is known.  The association patterns of males did not differ between maternal and non-maternal groups that contained an estrus female. Focal studies on estrus females (20) determined that nearest neighbor proximity was driven by the male sexual state of ‘musth’, regardless of relatedness. Moreover, estrus females directed affiliative behaviors toward musth males and negative behaviors towards non-musth males, regardless of relatedness. The results indicate that behavioral IA mechanisms in this small, closed population have broken down: male musth status overrides IA mechanisms. Fencing elephant populations carries a high risk of inbreeding.