Social affiliation among sub-adult male koalas in a high-density population

Darcy J. Watchorn

doi:10.1071/AM24033

RESEARCH ARTICLE (Open Access)

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Social affiliation among sub-adult male koalas in a high-density population

Darcy J. Watchorn ^A ^B ^*

+ Author Affiliations

- Author Affiliations

^A School of Life and Environmental Sciences (Burwood Campus), Deakin University, Geelong, Vic, Australia.

^B Wildlife Conservation and Science, Zoos Victoria, Parkville, Vic 3052, Australia.

^* Correspondence to: dwatchorn@deakin.edu.au

Handling Editor: Ross Goldingay

Australian Mammalogy 47, AM24033 https://doi.org/10.1071/AM24033

Submitted: 2 October 2024 Accepted: 8 January 2025 Published: 30 January 2025

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the Australian Mammal Society. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Koalas are generally considered to be a solitary species. However, during observations of free-ranging koalas in a high-density population, sub-adult males (3.5–5.5 years) were seen engaging in affiliative behaviours, including grooming, genital sniffing, and vocalising. These interactions were exclusive to males of this age group and are likely a result of the unusually high population density. In such populations, where home range overlap is common, these behaviours may help reduce stress, establish dominance hierarchies, and reduce conflict through familiarisation.

Keywords: animal behaviour, Koala, marsupial, Otway Ranges, Phascolarctos cinereus, population density.

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