Journal article

Supersize me: heavy eastern grey kangaroo mothers have more sons

Camille Le Gall-Payne, Graeme Coulson, Marco Festa-Bianchet



The Trivers-Willard hypothesis predicts that, in polygynous and sexually dimorphic mammals, mothers able to provide a large amount of care should produce more sons. Tests of this prediction, however, have generated equivocal results, possibly because multiple factors, including environmental conditions, simultaneously influence progeny sex ratio. We tested the influence of maternal mass, condition, size, previous reproduction and age class on offspring sex ratio in two populations of eastern grey kangaroos (Macropus giganteus). In one population, heavier and taller mothers produced more sons than did lighter mothers, but maternal condition had no effect on progeny sex ratio. Primiparous fema..

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University of Melbourne Researchers


Funding Acknowledgements

We are grateful to the contribution of students and field assistants over the years, especially E. Rioux Paquette, W. King, U. Gelin, A. Mackay, T. Allen, M. Wilson, S. Garnick and J. Cripps. This research was supported financially by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Australian Research Council (ARC) Linkage Program, the Ministere de l'Education, du Loisir et du Sport of Quebec (MELS), the Holsworth Wildlife Research Endowment, Parks Victoria and the Universite de Sherbrooke. We appreciate the logistic support of Parks Victoria and the Anglesea Golf Club.