Penile display of a young bull taking a mud bath,© Mélodie Busuttil

Dominance and thermo-regulatory functions of male African elephant penil displays
 
African elephants (Loxodonta africana) are known for their socially complex life. Males become adolescents between the ages of 10 and 20. During puberty and sexual maturation, young males go through a process of gaining independence from the natal herd to join all-male bull groups.  After the age of 20, they start experiencing an annual musth phase which is characterised by highly competitive social interactions with other males. But there is comparably little research on all-male groups and their social lives apart from the female herds.
 
A particularly bizarre behaviour documented by young bulls when approaching bigger and older bulls is the display of the erect penis, suggesting that this behaviour functions in social interactions. It has also been noticed that younger bulls engage in this display when approaching a vehicle, suggesting that this behaviour is a demonstration of dominance. However, bulls have also been seen to display their erect penises when entering a water dam where they then start with splashing the water onto it, especially on hot days, suggesting some sort of thermoregulatory function.
 
My master thesis will be on collecting data to address these two hypotheses of male elephant penile displays, i.e. the social dominance hypothesis and the thermo-regulatory hypothesis. My research will be supervised by Professor Klaus Zuberbühler (Comparative Cognition, University of Neuchâtel), Dr Michelle Henley (University of South Africa) and Dr Lucy Bates (University of Sussex, England). Data collection will take place in the Associated Private Nature Reserves (APNR) of the greater Kruger area, South Africa, over a period of six months in 2017.

A bull community taking a bath in a waterhole in the the Balule Private Game reserve (South Africa), © Mélodie Busuttil