Serpents in Paradise Burmese Pythons Invade Florida

Imported pythons are multiplying in Florida and eating their way through the state’s unique fauna. The main problem is pet owners who release their Asian jungle snakes into the wild. But biologists have a high-tech ploy to keep the plague in check.

Florida's a popular place: Not only is it a huge tourist destination, it also has one of the highest growth rates over the last 15 years of any American state. But humans aren’t the only species arriving here in droves. It’s possible that many thousands of Burmese pythons, which can grow up to seven meters long, are currently writhing through Florda's native undergrowth. In the suburbs of Miami they gobble turkeys and cats; in the Everglades they engage in battle with alligators.

"Python molurus bivittatus," as the snake is known to scientists, is native to southeast Asia, but the snake is shipped all over the world as a pet. In Florida you can buy baby Burmese pythons for $20. They start at 50 centimeters (20 inches) long, but within a year they can grow up to two meters (over six feet). Some owners find they can’t buy enough live rabbits to feed their growing python, and simply set the insatiable creature free.

The first giant pythons appeared in the Everglades tropical swamp in southern Florida 20 years ago. "But it was always just a few specimens," says Skip Snow, a biologist in the Everglades National Park.

Now there's evidence of an invasion: Last year Snow and the park’s rangers found 95 of the exotic snakes; this year it was 150. These sightings must represent just a fraction of the snakes that have settled throughout the park as well as in other parts of Florida. Recently Skip Snow and his colleagues have spotted very young pythons in the swamps -- which means the giant snakes have started to breed.

Eating their way through Florida?

The Burmese pythons are not the first imported creatures to thrive in the wild in Florida. The warm climate of this tourist paradise also offers excellent conditions for amphibians, reptiles and fish that have escaped or been set free. Boa constrictors, for example, breed in a park south of Miami. But their territory is surrounded by city neighborhoods and the Atlantic Ocean, which has so far made it impossible for them to escape.

Burmese pythons, though, could eat their way right across Florida. They're much bigger than than the 45 species of snake native to the state, and they have a larger appetite. With lightning speed they curl around their prey, choke the animal to death and devour it whole, swallowing skin, hair and feathers. Pythons hunt on the ground, in the water and in the branches of swamp cypresses, which makes them a new threat to Florida’s unique fauna.

Snow has cut open the stomachs of captured pythons and found the remains of bobcats, raccoons, opossums, as well as large birds like egrets, grebes, white ibises, and limpkins. The snakes even dare to attack alligators, but sometimes their eyes are bigger than their stomachs. One photograph that made headlines last year showed a four-meter-long python which had tried to choke down a two-meter-long alligator. Its stomach split open. Neither animal survived.

Even visitors and residents of Florida aren't safe from the giant snakes. "Humans don't belong to their natural prey," Snow says. "But Burmese pythons are perfectly capable of killing a human." A few owners have even been suffocated by their own pet snakes. Still, anyone can buy a constrictor without having to provide identification. No one can know what the owner intends to do with the snake.

Some politicians are now considering ways to restrict the buying and selling of dangerous snakes. They also want to introduce a "day of amnesty" on which weary owners can turn over their pets for disposal at certain public locations. But this won’t solve the problem of ex-exotic pets already living in the wild. It would be impossible to gather up all the freed Burmese pythons because the Florida swamps are far too big and the snakes' yellow-brown camouflage is too good. "Even someone standing right next to one would hardly notice it," says Snow. Most of the pythons he's managed to catch were basking in the sun on the street.

A project to develop a python trap hasn’t gotten far because of a lack of personnel and money. Attempts to train a sniffer dog ("Python Pete") are still in very early stages. Snow is now pursuing the idea of releasing female pythons into the wild as lures. Last week, four females were at large in the Everglades with tiny radio transmitters implanted under their skin. The hope is that these females will lead the rangers to hidden breeding areas during the upcoming mating season.