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Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE

Faecal DNA detection of invasive species: the case of feral foxes in Tasmania

Oliver Berry A C , Stephen D. Sarre A , Lachlan Farrington A B and Nicola Aitken A
+ Author Affiliations
- Author Affiliations

A Institute for Applied Ecology, University of Canberra, ACT 2615, Australia.

B Present address: School of Earth and Environmental Sciences, The University of Adelaide, SA 5005, Australia.

C Corresponding author. Present address: Invasive Animals Co-operative Research Centre and School of Animal Biology (M092), The University of Western Australia, Crawley, WA 6009, Australia. Email: ofb@cyllene.uwa.edu.au

Wildlife Research 34(1) 1-7 https://doi.org/10.1071/WR06082
Submitted: 6 July 2006  Accepted: 29 January 2007   Published: 27 February 2007

Abstract

Early detection of biological invasions is critical to reducing their impact, but because invading organisms are initially at low densities, detection and eradication can be challenging. Here, we demonstrate the utility of faecal DNA analysis for the detection of an elusive invasive species – the red fox, Vulpes vulpes, which was illegally introduced to the island of Tasmania in the late 1990s. Foxes are a devastating pest to both wildlife and agriculture on the Australian mainland, and would have a similarly serious impact in Tasmania if they became established. Attempts to eradicate foxes from Tasmania have been hampered by unreliable distribution data derived mostly from public sightings. In response, we developed a highly accurate and reliable DNA-based PCR-multiplex test that identifies foxes from field-collected faeces. We also developed a sexing test, but it was reliable only for faeces less than three weeks old. Faeces are a useful target for DNA-based diagnostics in foxes because they are deposited in prominent locations and are long-lasting. The species identification test formed a key component of a Tasmania-wide detection and eradication program. In all, 1160 geo-referenced carnivore scats were analysed; of these, 78% contained DNA of sufficient quality for species identification. A single scat from the north-east of the island was identified as belonging to fox, as was a nine-week-old roadkill carcass from the north coast, and a blood sample from near Hobart, triggering increased control and surveillance in these regions. The accuracy, reliability, and cost-effectiveness of non-invasive tests make them a critical adjunct to traditional tools for monitoring cryptic invasive species that are at low density in the early stages of invasion and when eradication is still an option.


Acknowledgements

This research was funded by a grant from the Hermon Slade Foundation. We thank Nancy Fisher, Arthur Georges, Bernd Gruber, Steve Lapidge, Nick Mooney, Linda Overend, Maxine Piggott, Gerhardt Reubel, Paul Sunnucks, Andrea Taylor, Rachel Walsh, Steve Zabar, the UC Wildlife Genetics Laboratory, and UWA population genetics for discussions and assistance. The constructive comments of two reviewers improved the manuscript. We also thank staff from CSIRO Gungahlin, and the Cooperative Research Centre for Pest Animal Control for assistance with the field trial, and the Fox-Free Tasmania Taskforce for diligent scat collection.


References

Adams, J. R. , Kelly, B. T. , and Waits, L. P. (2003). Using faecal DNA sampling and GIS to monitor hybridisation between red wolves (Canis rufus) and coyotes (Canis latrans). Molecular Ecology 12, 2175–2186.
Crossref | GoogleScholarGoogle Scholar | PubMed | McLeod R. (2004). Counting the Cost: Impact of Invasive Animals in Australia 2004. Cooperative Research Centre for Pest Animal Control, Canberra. 70 pp.

Meyers-Wallen, V. N. , Palmer, V. L. , Acland, G. M. , and Hershfield, B. (1995). SRY-negative XX sex reversal in the American cocker spaniel dog. Molecular Reproduction and Development 41, 300–305.
Crossref | GoogleScholarGoogle Scholar | PubMed | Sambrook J., Fritsch E. F., and Maniatis T. (1989). ‘Molecular Cloning: a Laboratory Manual.’ 2nd edn. (Cold Spring Harbor Laboratory Press: New York.)

Saunders G., Coman B., Kinnear J. E., and Braysher M. (1995). ‘Managing Vertebrate Pests: Foxes.’ (Australian Government Publishing Service: Canberra.)

Saunders G., Lane C., Harris S., and Dickman C. (2006). Foxes in Tasmania: A report on the incursion of an invasive species. Invasive Animals Cooperative Research Centre, Canberra. 93 pp.

Short, J. , and Smith, A. (1994). Mammal decline and recovery in Australia. Journal of Mammalogy 75, 288–297.
Crossref | GoogleScholarGoogle Scholar | Sokal R. R., and Rohlf F. J. (1995). ‘Biometry: The Principles and Practice of Statistics in Biological Research.’ 3rd edn. (W.H. Freeman and Co.: New York.)

Taberlet, P. , Waits, L. P. , and Luikart, G. (1999). Noninvasive genetic sampling: look before you leap. Trends in Ecology & Evolution 14, 323–327.
Crossref | GoogleScholarGoogle Scholar | Triggs B. (1996). ‘Tracks, Scats and Other Traces: a Field Guide to Australian Mammals.’ (Oxford University Press: Melbourne.)