When to declare successful eradication of an invasive predator?

Rout, T. M., Kirkwood, R., Sutherland, D. R., Murphy, S. and McCarthy, M. A. (2014) When to declare successful eradication of an invasive predator?. Animal Conservation, 17 2: 125-132. doi:10.1111/acv.12065

Author Rout, T. M.
Kirkwood, R.
Sutherland, D. R.
Murphy, S.
McCarthy, M. A.
Title When to declare successful eradication of an invasive predator?
Journal name Animal Conservation   Check publisher's open access policy
ISSN 1367-9430
Publication date 2014-01-01
Year available 2013
Sub-type Article (original research)
DOI 10.1111/acv.12065
Open Access Status Not yet assessed
Volume 17
Issue 2
Start page 125
End page 132
Total pages 8
Place of publication Oxford, United Kingdom
Publisher Blackwell
Language eng
Abstract Imperfect detection methods make it difficult to tell whether an invasive species has been successfully eradicated. However, management cannot continue indefinitely when individuals are no longer detected - at some point, efforts must be reduced or ceased entirely. The risks of mistakenly inferring that an eradication attempt has been successful can be high: the species can bounce back and even expand its range, causing environmental and economic damage, and rendering the initial eradication campaign redundant. This decision problem, balancing the risks of declaring eradication prematurely with the costs of continued management, is currently being contemplated by managers of the fox eradication programme on Phillip Island, in Victoria, Australia. We used a Bayesian catch-effort model to analyse data on the number of foxes removed and sighted using different methods. We estimate that there were 11 foxes remaining on Phillip Island as of end of June 2012. Baiting was the most effective method for removing foxes per person-hour invested, and spotlighting was the most effective method for sighting foxes without removal. We then projected forward into the future, assuming management effort continues at current levels, but no further foxes are detected (removed or sighted). Under this scenario, the mean estimate for the number of foxes remaining drops below a single fox after three years with no detections, and the probability that eradication has been successful is 0.69. This is the optimal time to declare eradication, given our estimated cost of declaring eradication prematurely. This framework indicates the minimum number of years for which management of foxes on the island must continue and allows decision makers to assess the trade-offs involved in any decision to declare eradication.
Keyword Bayesian statistics
Catch-effort models
Decision theory
Vulpes vulpes
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Biological Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 13 times in Thomson Reuters Web of Science Article | Citations
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