title: Environmental temperatures, physiology and behavior limit the range expansion of invasive Burmese pythons in southeastern USA.
abstract: A well-established population of Burmese pythons resides in the Everglades of southern Florida. Prompted in part by a report that identified much of southern USA as suitable habitat for expansion or establishment of the Burmese python, we examined the plausibility of this snake to survive winters at sites north of the Everglades. We integrated daily low and high temperatures recorded from October to February from 2005-2011 at Homestead, Orlando and Gainesville, Florida; and Aiken, South Carolina, with minimum temperatures projected for python digestion (16 °C), activity (5 °C) and survival (0 °C). Mean low and high temperatures decreased northward from Homestead to Aiken and the number of days of freezing temperatures increased northward. Digestion was impaired or inhibited for 2 months in the Everglades and up to at least 5 months in Aiken, and activity was increasingly limited northward during these months. Reports of overwinter survivorship document that a single bout of low and freezing temperatures results in python death. The capacity for Burmese pythons to successfully overwinter in more temperate regions of the USA is seemingly prohibited because they lack the behaviors to seek refuge from, and the physiology to tolerate, cold temperatures. As tropical Southeast Asia is the source of the Everglades Burmese pythons, we predict it is unlikely that they will be able to successfully expand to or colonize more temperate areas of Florida and adjoining states due to their lack of behavioral and physiological traits to seek refuge from cold temperatures.
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Jacobson
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: David G
authors.initials: DG
authors.lastname: Barker
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: Tracy M
authors.initials: TM
authors.lastname: Barker
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Mauldin
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Avery
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Engeman
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FloridaVida Preciosa International (VPI), Boerne, TexasUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, ColoradoUS Department of Agriculture, Wildlife Services, National Wildlife Research Center, Gainesville, FloridaDepartment of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Secor
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001833:Body Temperature Regulation / Q000502:physiology; D017821:Boidae / Q000502:physiology*; D003710:Demography; D004777:Environment; D005431:Florida; D058865:Introduced Species; D013022:South Carolina; D013696:Temperature