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Can invasive Burmese pythons inhabit temperate regions of the southeastern United States?


Understanding potential for range expansion is critical when evaluating the risk posed by invasive species. Burmese pythons (Python molurus bivittatus) are established in southern Florida and pose a significant threat to native ecosystems. Recent studies indicate that climate suitable for the species P. molurus exists throughout much of the southern United States. We examined survivorship, thermal biology, and behavior of Burmese pythons from South Florida in a semi-natural enclosure in South Carolina, where winters are appreciably cooler than in Florida, but within the predicted region of suitable climate. All pythons acclimated to the enclosure, but most died after failing to seek appropriate refugia during sub-freezing weather. The remaining snakes used refugia but died during an unusually cold period in January 2010. Although all snakes died during the study, most survived extended periods at temperatures below those typical of southern Florida and none exhibited obvious signs of disease. Our study represents a first step in evaluating the results of climate matching models and we address factors that may affect range expansion in this invasive species.

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We thank R. Bauer and S. Poppy for assisting with many aspects of the study and helping to track snakes. For assistance with various project logistics and advice, we thank K. Andrews, M. Cherkiss, B. DeGregorio, J. Greene, C. Hagen, K. Hart, E. Kabela, F. Mazzotti, T. Mills, S. Pfaff, M. Pilgrim, M. Rochford, S. Snow, T. Tuberville, A. Tucker, T. Walters, and A. Wolfe. R. Snow provided and transported animals. We especially thank R. McManamon and B. Ritchie from the Univ. of Georgia School of Veterinary Medicine who conducted necropsies. E. Eskew assisted with calibrating dataloggers. S. Foley assisted with data analysis. E. Eskew, S. Price, K. Hart, R. Reed, R. Snow, and two anonymous reviewers all provided comments on the manuscript. All procedures used in the study were approved by the University of Georgia Animal Care and Use Committee (no. A2009 2-041). Pythons were collected under scientific collecting permit #EVER-2009-SCI-0001 issued by the NPS. This material is based upon work supported by the US Dept. of Energy under Award Number DE-FC-09-075R22506 to the University of Georgia’s Savannah River Ecology Lab. Partial funding was provided by the Davidson College Department of Biology and Duke Power.

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Correspondence to Michael E. Dorcas.

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Dorcas, M.E., Willson, J.D. & Gibbons, J.W. Can invasive Burmese pythons inhabit temperate regions of the southeastern United States?. Biol Invasions 13, 793–802 (2011).

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