Forget humane removal. Scientists studying the invasive giant Burmese pythons that infest Florida have discovered the snakes can find their way home even when taken up to 20 miles away.
The snakes homing ability is "on a scale previously undocumented for any snake species," said Shannon Pittman, a herpetologist at Davidson College in Davidson, N.C.. With the snakes spreading south and north, the implications for surrounding states and areas that have been colonized are worrisome.
The research appears Wednesday in the journal Biology Letters.
Researchers at Davidson and the U.S. Geological Survey trapped six Burmese pythons in Florida and placed radio transmitters in them. They then took them 13 to 20 miles away and released them.
The snakes immediately headed back, taking "direct and striking" routes, said Kristen Hart, a research ecologist with the USGS in Gainesville, Fla.
It took the snakes 94 to 296 days to return but eventually they navigated to within 3 miles of their original capture locations in Everglades National Park.
The research shows that moving the snakes won't work as a control strategy. "You can't move them. Quite honestly, they're going to move back to where they came from," Hart said.
No one knew Burmese pythons were capable of homing.
Researchers don't know how the snakes do it. It could be by sight or smell or even the Earth's magnetic field.
Burmese pythons are one of the world's largest snakes. An 18-foot specimen was found in the Everglades on Feb. 4.
Native to southern Asia, the snakes began to appear in south Florida in the late 1990s, probably released by pet owners.
They have since colonized hundreds of square miles in southern Florida, including most of Everglades National Park and Big Cypress National Preserve.
While more than 2,000 Burmese pythons have been re
moved from the area since 2002, the National Park Service estimates that represents only a fraction of the total population.
"There are records of snakes up nearly to Lake Okeechobee," said Michael Dorcas, a biology professor at Davidson College and lead author on the paper. "Most scientists agree that they are likely well north of Alligator Alley (I-75) now."
The snakes are devastating invaders, eating a wide variety of animals including deer and alligators. "They're eating through the food chain," Hart said.