Age classes of the greater bilby (Macrotis lagotis) based on track and faecal pellet size
Richard SouthgateBiodiversity Conservation Unit, Department of Infrastructure, Planning and Environment, PO Box 2130, Alice Springs, NT 0871, Australia. Current address: PO Box 305, Kingscote, SA 5223, Australia and School of Earth and Environmental Sciences, University of Adelaide, SA 5006, Australia. Email: southgate@kin.net.au
Wildlife Research 32(7) 625-630 https://doi.org/10.1071/WR03088
Submitted: 16 September 2003 Accepted: 23 August 2005 Published: 24 November 2005
Abstract
The gait length and width and faecal pellet diameter of bilbies were examined to determine whether these measures could be used to accurately identify different age classes of individuals in the field. There was a good relationship between gait width+length and animal size that allowed the identification of three age classes: immature–independent individuals <500 g, mature females and small males 500–1200 g, and large males >1700 g. The relationship between pellet diameter and animal size was not as strong and faecal pellet diameter was suitable to identify only immature–independent individuals. An application of these measurements to a bilby population in the Tanami Desert indicated that immature individuals were limited to the central half of their current distribution whereas medium-sized individuals were distributed throughout.
Acknowledgments
The study was funded by the Department of Infrastructure, Planning and Environment of the Northern Territory, the World Wide Fund for Nature and the Department of Environment and Heritage. I thank Shona Whitfield, Kathryn Romanow, Keith Bellchambers and Pip Masters for their assistance with data collection at WNP. Pip Masters, Ada Nano, Don Langford, Chris Grant and Rachel Paltridge assisted with data collection in the Tanami Desert. The work in the Tanami Desert was also supported considerably by Irene Driver Nungarrayi, Tommy Driver Jupurrula, Peter Bartlett, Cindy Gibson Nakamarra, Mitjili Gibson Napangangka. Comments by Pip Masters, Rachel Paltridge, Sue Carthew and two anonymous referees greatly improved the manuscript.
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