Dietary strategy of the swamp antechinus (Antechinus minimus maritimus) (Marsupialia : Dasyuridae) in coastal and inland heathland habitats
Louise M. Allison A B , Lesley A. Gibson A C D and John G. Aberton AA School of Ecology and Environment, Deakin University, Geelong, Vic. 3217, Australia.
B Present address: Earth Tech, 71 Queens Road, Melbourne, Vic. 3001, Australia.
C Present address: Department of Conservation and Land Management, Wildlife Research Centre, PO Box 51, Wanneroo, WA 6946, Australia.
D Corresponding author. Email: lesleyg@calm.wa.gov.au
Wildlife Research 33(1) 67-76 https://doi.org/10.1071/WR05038
Submitted: 18 April 2005 Accepted: 25 November 2005 Published: 7 March 2006
Abstract
In the coastal heathlands of southern Victoria, populations of a rare dasyurid, the swamp antechinus (Antechinus minimus maritimus), are restricted to small and disjunct patches of suitable habitat. Although characteristics of their preferred habitat in terms of vegetation structure and composition have been described, little is known of their diet preferences. Diet and food availability of the species was examined at two coastal and two inland sites, during winter and spring by way of faecal analyses and pitfall trapping. Only minor differences in diet were observed between the coastal and inland habitats and this was consistent across season. There was, however, variation in food availability between the two habitat types, with generally higher frequencies of invertebrates occurring within the inland than in the coastal habitat during spring. Even so, when diet was directly compared with food availability, the differences observed within individual categories within each season were similar in magnitude and direction for both habitats, suggesting that inland and coastal populations of the swamp antechinus have similar dietary strategies. Insect larvae, Diplopoda and Coleoptera appeared to be favoured dietary items being almost consistently over-represented in the diet compared to their availability, whereas Collembola, Amphipoda, Dermaptera and Formicidae were avoided as they were never consumed in proportion to their availability. Although dietary preferences were evident, there was no clear selection of any one particular prey item, and so the swamp antechinus was considered a dietary generalist. Also, as the species sampled from most of the range of prey items available to them, it fits the qualitative criterion of opportunism. The generalist strategy of the swamp antechinus is likely to be advantageous in an environment subject to disturbance.
Acknowledgments
We are grateful to Susie Schickman for laboratory assistance. The study was partially funded by the Field Naturalist Club of Victoria. The research was conducted under a Department of Sustainability and Environment Scientific Permit and with ethics approval from Deakin University Animal Ethics Committee.
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