title: The Role of Bioacoustic Signals in Koala Sexual Selection: Insights from Seasonal Patterns of Associations Revealed with GPS-Proximity Units.
abstract: Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus--the only extant member of the family Phascolarctidae) is poorly known and much of the koala's sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas.
authors.affiliation: School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: William
authors.initials: W
authors.lastname: Ellis
authors.affiliation: School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: FitzGibbon
authors.affiliation: San Diego Zoo Global, P.O. Box 120551, San Diego, California 92112-0551, United States of America.
authors.forename: Geoff
authors.initials: G
authors.lastname: Pye
authors.affiliation: San Diego Zoo Global, P.O. Box 120551, San Diego, California 92112-0551, United States of America.
authors.forename: Bill
authors.initials: B
authors.lastname: Whipple
authors.affiliation: School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Ben
authors.initials: B
authors.lastname: Barth
authors.affiliation: School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Johnston
authors.affiliation: Faculty of Veterinary Science, The University of Queensland, Brisbane, Queensland, 4072, Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Seddon
authors.affiliation: CQUniversity, Koala Research Centre of Central Queensland, School of Medical and Applied Sciences, Rockhampton, Queensland, 4702, Australia.
authors.forename: Alistair
authors.initials: A
authors.lastname: Melzer
authors.affiliation: Faculty of Veterinary Science, The University of Sydney, Sydney, Australia.
authors.forename: Damien
authors.initials: D
authors.lastname: Higgins
authors.affiliation: Kyoto University Primate Research Institute & Wildlife Research Center, 41-2 Kanrin, Aichi, Inuyama, 484-8506 Japan.
authors.forename: Fred
authors.initials: F
authors.lastname: Bercovitch
mesh_terms: D000162:Acoustics; D000818:Animals; D000835:Animals, Wild; D005260:Female; D040362:Geographic Information Systems; D008297:Male; D048368:Phascolarctidae / Q000502:physiology*; D011793:Queensland; D012621:Seasons; D012737:Sex Factors; D012726:Sexual Behavior, Animal; D014828:Vocalization, Animal