Threatened Species - Sandhill Dunnart
Sandhill Dunnart
The Sandhill Dunnart Sminthopsis psammophila was recently found on Eyre Peninsula after not being seen there for 30 years. The population is small and appears to be limited to a series of sand dunes that have escaped the ravages of several extensive fires over the last 15 years. An adult female and five recently weaned and independent juveniles were captured in January 2000. They were radio tracked to their daytime retreats and found to use large hummocks of spinifex Triodia irritans. These large hummocks were mainly restricted to the slopes of the unburnt dunes. Spinifex Life StagesThe life stage of spinifex used for daytime shelter was not random. The dunnarts rejected several clumps before selecting one with the appropriate structure. Their preferred shelter was large spinifex, which had started to die off in the centre. These formed an almost intact wall of spines but the dead central spines were soft and easily molded into a chamber. The selected spinifex was first examined by the dunnart around the periphery and rejected if the ground level cover was not intact. When an appropriate clump was found the dunnart clambered over the top of the clump and burrowed down into the centre.
A large sample of spinifex clumps adjacent to the trap lines was measured to determine the percentage within each growth stage. It was found that, although 94% of the day shelters were in spinifex 'stage 3', this stage of development constituted only 6% of the available spinifex. Each dunnart was found to use several different 'stage 3' spinifex clumps as daytime retreats, using a different one each day but returning to favourites every third or fourth day. Micro-climate ConsiderationsAs well as providing predator protection, 'stage 3' spinifex moderates the micro-climate.
Conclusions
The implication of this work is that Sandhill Dunnarts may be dependent on specific growth stages of spinifex for their continued presence in an area. Factors such as recent burning or absence of burning may render a location unsuitable for these animals for many years. Sandhill Dunnarts have previously been captured at only a few widespread locations in the Great Victoria Desert of Western and South Australia, and the Eyre Peninsula. Examination of the use of spinifex by sandhill dunnarts may help define the potential trapping sites for surveys currently being conducted in the Great Victoria Desert. Program SupportAuthorSue Churchill, Project Officer, Department for Environment and Heritage ContactPeter Copley, Senior Ecologist, Threatened Species, Department for Environment and Heritage |
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