1. Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Allingham Street, Armidale, New South Wales 2350, Australia.
2. Ecosystem Management, School of Environmental and Rural Science, University of New England, Ring Road North, Armidale, New South Wales 2351, Australia.
3. Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Forest Road, Orange, New South Wales 2800, Australia.
4. Vertebrate Pest Research Unit, NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, New South Wales 2450, Australia.