Function of Trunk-Mediated “Greeting” Behaviours between Male African Elephants: Insights from Choice of Partners
Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QG, UK
Elephants for Africa, 5 Balfour Road, London N5 2HB, UK
School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
Department of Neuroscience, University of Pennsylvania, Philadelphia, PA 19104, USA
Author to whom correspondence should be addressed.
These authors contributed equally.
Academic Editors: Angela S. Stoeger and Anton Baotic
Received: 24 August 2021
Revised: 9 September 2021
Accepted: 14 September 2021
Published: 17 September 2021
Despite our common connotations with the term “greeting”, such behaviours in non-human societies are not exclusively employed in the context of reunion. For example, these multimodal signals can function to test bonds, promote cooperation, or facilitate further positive interactions between individuals, as well as to ease tension and update uncertain relationships at reunion events. A common behaviour in male elephants is for a male to direct his trunk to a same-sex conspecific’s mouth, temporal gland, or genitals. Such behaviours are often labelled as greetings, and in addition to being gestural and tactile signals, may simultaneously enable olfactory assessment of aspects of the target male’s phenotype. We analysed trunk-mediated greetings performed by different aged male elephants at aggregations in an all-male area. Despite considerable mixing of new potential interactors, in a system with high fission-fusion dynamics, we found no evidence that males preferentially targeted elephants met new at aggregations with greetings. Adolescents greeted at higher rates than adults. All males, apart from older adolescents preferably greeted age-matched males. In male-male elephant communication, these behaviours likely function to facilitate further positive interaction, or assess aspects of phenotype between similar aged males occupying the same ecological space, rather than as a reunion display.