NEWS RELEASE
The Center for North American Herpetology
Lawrence, Kansas
*http://*www.cnah.org
13 August 2008
CLAIMS OF POTENTIAL EXPANSION THROUGHOUT THE U.S. BY INVASIVE PYTHON SPECIES ARE CONTRADICTED BY ECOLOGICAL NICHE MODELS
2008. R. Alexander Pyron, Frank T. Burbrink & Timothy J. Guiher
Public Library of Science One 3(8): 1-7
Background: Recent reports from the United States Geological Survey (USGS) have suggested that invasive Burmese Pythons [Python molurus bivittatus, aka Indian Python, P. molurus] in the Everglades may quickly spread into many parts of the U.S. due to putative climatic suitability. In addition, projected trends of global warming were predicted to
significantly increase the suitable habitat and promote further expansion of the snakes.
The suggestion of an imminent giant python invasion has generated significant interest in the media, which in turn has spurred warnings of the dangers of pet- and man-eating
snakes spreading throughout the U.S. However, the ecological limitations of the Burmese Python with respect to further expansion are not known. Additionally, the possible effects
of global warming on the continued existence of the species and their further colonization of the United States are also unclear.
Methodology/Principal Findings: Here we show that a predicted continental expansion is highly unlikely, based on the ecology of the organism and the climate of the U.S. Our ecological niche models, which include variables representing climatic extremes as well as averages, indicate that the only suitable habitat in the U.S. for Burmese Pythons presently occurs in Everglades National Park in southern Florida and in extreme southern Texas.
Models based on the current range of the snake primarily predict suitable habitat in the only region the snakes have ever been found in the U.S. Future climate models based on global warming forecasts actually indicate a contraction in suitable habitat for Burmese Pythons in the U.S. as well as in their native range, highlighting the significant impact global climate change may have on biodiversity.
Conclusions/Significance: The Burmese Python is limited to a small area of suitable environmental conditions in the United States due to the ecological preferences of the snake. The ability of the Burmese Python to expand further into the U.S. is severely limited by ecological constraints. Global warming is predicted to significantly reduce the area of suitable habitat worldwide, underscoring the potential negative effects of climate change for many species.
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