Koalas continue to occupy their previous home-ranges after selective logging in Callitris–Eucalyptus forest
Rodney P. Kavanagh A B , Matthew A. Stanton A and Traecey E. Brassil AA Science and Research Division, Department of Primary Industries, PO Box 100, Beecroft, NSW 2119, Australia.
B Corresponding author. Email: rodk@sf.nsw.gov.au
Wildlife Research 34(2) 94-107 https://doi.org/10.1071/WR06126
Submitted: 26 September 2006 Accepted: 22 February 2007 Published: 24 April 2007
Abstract
The koala (Phascolarctos cinereus) is a charismatic, high-profile species whose conservation needs are commonly perceived to be incompatible with logging. However, koala biology and the results of chronosequence studies elsewhere suggest that this species may tolerate a degree of habitat alteration caused by logging. In this study, 30 koalas, five in each of six areas available for logging within a mixed white cypress pine (Callitris glaucophylla)–Eucalyptus forest in north-western New South Wales, were radio-tracked for one year during 1997–1998 to determine their movements, home-range sizes and tree preferences. Five months after the study began, three of these areas were logged selectively for sawlogs and thinnings of the white cypress pine, a tree that is important to koalas for daytime shelter. This removed about one-quarter of the stand basal area, but the eucalypt component was unaffected. The remaining three areas were left undisturbed as controls. Radio-tracking continued in all six areas for another seven months. Koalas continued to occupy all or part of their previous home-ranges after selective logging, and home-range sizes remained similar between logged and unlogged areas. Home-ranges for both sexes overlapped and were ~12 ha for males and 9 ha for females. Koala survival and the proportions of breeding females were similar in logged and unlogged areas. The principal food trees of the koala were red gums, mainly Eucalyptus blakelyi and E. chloroclada, and the pilliga box (E. pilligaensis), none of which were logged in this study. These results suggest that selective logging for white cypress pine does not appear to adversely affect koala populations and that koalas may not be as sensitive to logging as previously thought. Further work is required to determine thresholds in the level of retention of koala food trees in logging operations.
Acknowledgements
Special thanks go to J. Callaghan and S. Phillips (Australian Koala Foundation) and to J. McKee (University of Queensland), research collaborators in this and related aspects of the larger ‘Pilliga Koala Research Project’, for their enthusiasm and unstinting support. Their assistance, along with that of G. Lloyd, B. Fritz, T. Curran, R. Booth and many other volunteers, was essential for the location, capture, recapture and smooth processing of so many animals. The continuing interest, field assistance and logistic support by local and regional staff of State Forests of NSW and the National Parks and Wildlife Service was vital for the success of this project. In particular, we thank W. Bratby, S. Cottier, L. Carey, M. Linehan, P. Crichton, A. Williams, G. Daniels, P. Haywood, R. Madden, R. Skinner, D. Frater, and all the rest of the Forestry staff at Baradine. B. Law is thanked for his comments on the manuscript.
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