Widespread amphibian extinctions from epidemic disease driven by global warming


As the Earth warms, many species are likely to disappear, often because of changing disease dynamics. Here we show that a recent mass extinction associated with pathogen outbreaks is tied to global warming. Seventeen years ago, in the mountains of Costa Rica, the Monteverde harlequin frog (Atelopus sp.) vanished along with the golden toad (Bufo periglenes). An estimated 67% of the 110 or so species of Atelopus, which are endemic to the American tropics, have met the same fate, and a pathogenic chytrid fungus (Batrachochytrium dendrobatidis) is implicated. Analysing the timing of losses in relation to changes in sea surface and air temperatures, we conclude with ‘very high confidence’ (> 99%, following the Intergovernmental Panel on Climate Change, IPCC) that large-scale warming is a key factor in the disappearances. We propose that temperatures at many highland localities are shifting towards the growth optimum of Batrachochytrium, thus encouraging outbreaks. With climate change promoting infectious disease and eroding biodiversity, the urgency of reducing greenhouse-gas concentrations is now undeniable.

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Figure 1: Altitudinal patterns in the Atelopus extinctions.
Figure 2: AT and SST for the tropics and their relationship to climatic trends at Monteverde.
Figure 3: Signatures of warming in the Atelopus extinctions.
Figure 4: Daily minimum and maximum temperatures and the chytrid-thermal-optimum hypothesis.


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We thank T. P. Mitchell at JISAO and S. J. Worley at NCAR for help in obtaining climate data, R. A. Alford, F. Bolaños, J. P. Collins, R. O. Lawton, K. R. Lips, M. D. Mastrandrea, K. G. Murray, P. Ramírez and B. D. Santer for discussion, and the many contributors to the Atelopus database. S. H. Schneider, A. R. Blaustein and C. Parmesan commented on earlier drafts of the manuscript. The Declining Amphibian Populations Task Force and Conservation International's Critically Endangered Neotropical Species Fund provided partial funding to J.A.P. The Canada Foundation for Innovation and the Tinker Foundation helped produce the remote-sensing databases. The Research and Analysis Network for Neotropical Amphibians and the US National Science Foundation sponsored meetings that facilitated portions of the study. Author Contributions All authors after the first are listed alphabetically. J.A.P. conceived, designed and orchestrated the study, conducted most of the analyses (principally with J.A.C. and K.L.M.), formulated the chytrid-thermal-optimum hypothesis (with R.P.), and wrote the paper (with editing by J.A.C. and K.L.M.). M.R.B., L.A.C., M.P.L.F., E.L.M., A.M.-V. and S.R.R. provided key data and background information. E.L.M. compiled the Atelopus database (with B.E.Y.). P.N.F. conducted the climate simulations. G.A.S.-A. analysed the remote-sensing data. C.J.S. helped with the climate analyses and their interpretation. B.E.Y. obtained funding for meetings, provided logistics, and analysed GAA data for New World amphibians.

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Correspondence to J. Alan Pounds.

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Alan Pounds, J., Bustamante, M., Coloma, L. et al. Widespread amphibian extinctions from epidemic disease driven by global warming. Nature 439, 161–167 (2006). https://doi.org/10.1038/nature04246

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