(I know I also posted this to the herp law forum, but it seemed important enough to put here as well - I know many folks were interested in it...)

http://www.aikenstandard.com/Local/python-for-web2010-09-22T19-24-49

A study on the ability of Burmese pythons to survive in more temperate climates suggests there will be no python invasion in South Carolina any time soon.

A year-long study at the Savannah River Ecology Laboratory sought to determine whether pythons - now well established in the Florida Everglades - could survive winters at this latitude and the potential for a northward expansion.

Of the 10 pythons tracked, none survived the winter, all succumbing to one of the most brutal winters on record in South Carolina.

"Our results suggest that Burmese pythons from the population currently established in Florida are capable of withstanding conditions substantially cooler that those typically experienced in southern Florida but may not be able to survive severe winters in regions as temperate as central South Carolina," the researchers reported.

The research, published this morning online in the scientific journal "Biological Invasions," was a joint study between Davidson College and the University of Georgia, and was co-authored by Michael Dorcas, J.D. Willson and Whit Gibbons.

While all 10 snakes died over the winter, the researchers noted the severity of the 2009-2010 winter, and that further study was needed to determine what potential evolution and adaptation by the Asian snake could lead to northward population establishment.

"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 stated.

Dorcas said that, while an established population in South Carolina is not likely in the immediate future, the question of northward expansion remains unanswered.

"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," Dorcas said.

The ten snakes, ranging in size from six to 12 feet, were placed in an 80-foot by 100-foot pen, with a small pond in the middle and several large brush piles. Additionally, artificial underground dens were constructed for the snakes. The pen was surrounded by a smooth fence sunk in concrete to ensure they could not escape. All of the pythons were implanted with transmitters in order to track and monitor them. None of the snakes escaped the pen during the study.

Half of the snakes perished on Dec. 11, when temperatures dipped to around 25 degrees. Of those initial deaths, none of the snakes had sought cover or refuge in the artificial dens. Three more snakes died between Dec. 17 and Jan. 4, each having failed to seek cover during subzero temperatures. The last two snakes were found in underground cover in mid-January during an extreme cold spell.

Autopsies of the snakes revealed they died of acute hypothermia and had no signs of disease or respiratory infection.

The researchers noted that some Burmese pythons in other studies had adopted behaviors that would allow them to endure colder temperatures, and that, over time, those snakes could produce more cold-tolerant offspring. Those behaviors included seeking refuge during cold spells.

"If such variation in behavior is heritable, natural selection could result in a python population better adapted to cold weather," the study said.

The researchers concluded that the snakes may have survived a more moderate winter in South Carolina.

"Thus, it is likely that some of the snakes from Florida could survive typical winters in South Carolina, provided they are able to locate suitable refugia and do not adopt inappropriate thermoregulatory behavior," the study said.

And while an imminent invasion of the snakes was feared by some, the researchers said that, if the snakes can acclimate to the cold temperatures, it could take decades for them to be established here.

"It is important to remember that, although the time frame considered for expansion of the pythons' range in the United States is typically short-term (i.e., decades), it may take much longer for the species to spread into all regions of suitable climate and habitat," the study said.

Contact Michael Gibbons at mgibbons@aikenstandard.com.

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