Eventually the public will be able to transmit sightings, photos and GPS data to help authorities track invaders. The latest tactic on that front is a new smartphone app that serves as a field guide to the region's big reptiles. The current strategy focuses on containing the pythons' range, stubbing out isolated populations, and targeting areas where pythons are particularly destructive, such as near bird colonies. Not that he and other managers aren't trying. It's never been done, and we have no studies to go to, that say: 'Yep, if you do these things you can eradicate an introduced reptile.' Our toolbox is empty of proven tools," he said. "We have no proven eradication tools for introduced reptiles anywhere in the world, really. If Snow doesn’t sound very hopeful that the snakes can be eradicated, it's because they're so secretive, and the Everglades are vast, largely inaccessible, and full of hiding places. They're clearly here, and they're breeding and they're established and they're going to tell us over the years and over the decades just what they can put up with and how far they can go." What it all means for the pythons' ability to invade farther north remains to be seen, but Snow takes the long view: "The snakes are going to tell us. Whether the surviving pythons have genetically based adaptations to the cold is unknown, but if so, said Dorcas, "then we just had a major selection event for cold-tolerant pythons." That's about the same number of hatchlings found by this time last year, so clearly the wintry weather didn't set the population back much. In the months since the cold snap, adults and 24 hatchlings have been spotted in the wild, according to Snow. That sounds like a good proportion, but extrapolating to a population of thousands leaves plenty of snake survivors, said Skip Snow, a wildlife biologist based at Everglades National Park who contributed with Dorcas and others to the study. Nine of 10 radio-tagged pythons there died, researchers reported in another Biological Invasions paper, published online in June. The same cold snap that killed the South Carolina transplants also killed many Burmese pythons in the Everglades. But snakes had survived many nights where it got below freezing." "If we provided deeper refugia, well, would they have survived? We certainly had snakes that survived a long time and were finally killed by the extreme cold snap we had in January. "There are certainly in South Carolina much deeper retreats that they could have found if they were out in the wild, such as armadillo burrows," Dorcas said. Snakes born in the area might fare better than snakes transplanted in as adults.įinally, the pythons that survived the longest were the ones that crawled into underground cavities at night, and Dorcas wonders whether they might have fared even better outside the enclosure. For another, some studies indicate that the temperatures a snake experiences during its first year determine how it regulates its body temperature for the rest of its life. Still, said study leader Michael Dorcas of Davidson College in North Carolina, "there certainly is a possibility that pythons could survive in South Carolina and possibly even farther north."įor one thing, the subfreezing temperatures were highly unusual for the region. With temperatures dipping below freezing at night for long stretches, the 10 snakes died, according to a paper published in September online in the journal Biological Invasions. Then, in January, the region was plunged into an extremely unusual cold spell. After implanting a radio transmitter and a temperature logger in each snake, the researchers let them loose in June 2009 in a snake-proof outdoor enclosure.Īll 10 pythons did well through the summer and fall, and even survived 12 December nights that were no warmer than 41 degrees Fahrenheit (5 degrees Celsius). To test those predictions, researchers recently brought 10 adult male pythons from the Everglades to South Carolina, to see whether they could survive the cooler climate. Geological Survey in 2008 predicted the pythons could find suitable climate in about a third of the United States, as far north as Washington, D.C. After all, the species' native range includes the foothills of the Himalayas, so it is no stranger to cold. So far the Burmese python invasion is restricted to Florida's southern tip, but scientists have been debating whether it could spread to more temperate parts of the United States.
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