Distribution and Impacts of Tasmanian Devil Facial Tumor Disease
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The Tasmanian devil, Sarcophilus harrisii, is the largest extant marsupial carnivore. In 1996, a debilitating facial tumor was reported. It is now clear that this is an invariably lethal infectious cancer. The disease has now spread across the majority of the range of the species and is likely to occur across the entire range within 5 to 10 years. The disease has lead to continuing declines of up to 90% and virtual disappearance of older age classes. Mark-recapture analysis and a preliminary epidemiological model developed for the population with the best longitudinal data both project local extinction in that area over a timeframe of 10 to 15 years from disease emergence. However, the prediction of extinction from the model is sensitive to the estimate of the latent period, which is poorly known. As transmission appears to occur by biting, much of which happens during sexual encounters, the dynamics of the disease may be typical of sexually transmitted diseases. This means that transmission is likely to be frequency-dependent with no threshold density for disease maintenance. Extinction over the entire current range of the devil is therefore a real possibility and an unacceptable risk.
KeywordsTasmanian devil infectious cancer extinction disease ecology
H.M., M.J., and S.L. are partially funded under an Australian Research Council Linkage Grant. We are grateful to a large number of volunteers who have made this work possible. All fieldwork was carried out under animal ethics approvals to the University of Tasmania, The University of Queensland, and the Tasmanian Department of Primary Industries and Water.
- Gog J, Woodroffe R, Swinton J (2002) Disease in endangered metapopulations: the importance of alternative hosts. Proceedings of the Royal Society of London. Series B: Biological Sciences (London) 269:671–676Google Scholar
- Hamede R, Jones ME, McCallum H (2007) Seasonal, demographic and density-related patterns of contact between Tasmanian devils (Sarcophilus harrisii): Implications for transmission of devil facial tumour disease. Austral Ecology (in press)Google Scholar
- Lachish S, Jones ME, McCallum HI (2007) The impact of devil facial tumour disease on the survival and population growth rate of the Tasmanian devil. Journal of Animal Ecology 76:926–936Google Scholar
- McCallum H, Dobson A (2002) Disease, habitat fragmentation and conservation. Proceedings of the Royal Society of London. Series B: Biological Sciences (London) 269:2041–2049Google Scholar
- Pemberton D (1990) Social organisation and behaviour of the Tasmanian devil, Sarcophilus harrisii. Ph.D. thesis, University of TasmaniaGoogle Scholar