Burmese Pythons Don't Survive Cold Experiment

A story in the Aiken Standard (South Carolina) Monday, September 27, 2010 by Michael Gibbons reports that a study of 10 Burmese Pythons taken from Florida and held in an outdoor pen all died during an exceptionally cold January of 2010. Michael Dorcas was quoted as saying, "Our study helps to address the potential for range expansion in pythons, but many questions remain that must be addressed to fully evaluate the ability of this species to inhabit regions outside of southern Florida....The study tells us that pythons currently inhabiting south Florida may not be able to survive a winter in the Coastal Plain of South Carolina, but many questions remain that must be addressed before we can conclusively say they cannot survive here.."

The authors used ten snakes, ranging in size from six to 12 feet, and housed them in an 80-by100-foot pen, with a pool in the middle, large brush piles and artificial underground dens. All snakes had implanted transmitters. Half of the snakes died on December 11, when temperatures dropped to around 25 F. None of the snakes that died on 12/11/2009 had sought cover or refuge in the artificial dens. Three other snakes died between 12/7 2009and 1/4 2010 when they did not take refuge during subfreezing temperatures. The two surviving snakes were found in underground cover in mid January during an extreme cold spell. Autopsies revealed the animals died of acute hypothermia and showed no signs of disease or respiratory infection.

Other studies of Burmese Pythons suggested they could survive colder temperatures by seeking cover, and that, over time, those snakes might produce more cold-resistant offspring. The research has been published in Biological Invasions.

Dorcas, M. E., J. D. Wilson and J. W. Gibbons 2010. Can invasive Burmese pythons inhabit temperate regions of the southeastern United States? Biological Invasions. Online article.