Factors affecting female reproductive success and the survival of pouch young in the threatened brush-tailed rock-wallaby, Petrogale penicillata
Naomi M. Wynd A , Dominique P. Sigg A , Anthony R. Pople A B , Stephanie L. Hazlitt A and Anne W. Goldizen A CA School of Integrative Biology, University of Queensland, St Lucia, Qld 4072, Australia.
B Current address: Department of Natural Resources and Mines, GPO Box 2454, Brisbane, Qld 4001, Australia.
C Corresponding author. Email: a.goldizen@uq.edu.au
Australian Journal of Zoology 54(2) 61-70 https://doi.org/10.1071/ZO05064
Submitted: 19 October 2005 Accepted: 8 March 2006 Published: 11 May 2006
Abstract
Knowledge of factors affecting the survival of individuals and their reproductive success is essential for threatened species management, but studies assessing these factors are lacking for many threatened rock-wallaby species. In this study we investigated the factors influencing the breeding performance of females and the survival of pouch young in a wild colony of the threatened brush-tailed rock-wallaby. Individuals were trapped between October 2000 and April 2004. More than 50% of the females in the colony were breeding below their full potential and giving birth to only one offspring per year. Most females within the colony bred in synchrony, with a substantial birth peak evident during autumn. Pouch young born in autumn left the pouch during spring and were weaned during summer and autumn when forage was most abundant. Pouch young born during the autumn birth peak or in winter had a substantially higher probability of surviving through to pouch emergence than those born during spring or summer. This study provides demographic parameters that may be used in population models and for comparison with other populations, particularly those that are small and declining. To optimise reproductive success in reintroduction programs, females in good condition and with small pouch young should be released at the end of the wettest season.
Acknowledgments
We thank the Robert Moore family for permission to work on their land and J. and K. Carter, Rebecca Laws and volunteers for their assistance in the field. Thank you to D. Pavlacky, D. Putland and the Behavioural Ecology Research Group at the University of Queensland (UQ) for statistical help and comments on earlier drafts of this manuscript. Thank you to Robert Laws and G. Maggs from Queensland Parks and Wildlife Service (QPWS) for their much appreciated assistance in the field. This study was authorised by the University of Queensland Animal Ethics Committee and a QPWS Scientific Purposes Permit. The study was supported by funding provided to A. W. G. from the Australian Research Council, the National Geographic Society and the University of Queensland.
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