The meandering trail in the Everglades marshlands was made by alligators, I’m told, so be careful. There’s also poisonwood, fire ants and the recently added Burmese python.
“It’s really a very harsh place to work,” says Kristen M. Hart, a research ecologist for the U.S. Geological Survey and a close follower of the python, which has invaded the Everglades in startling numbers.
“We don’t know how many there are,” Hart says, “and that’s ultimately the question everyone wants to know.”
She reckons tens of thousands in the Everglades, but allows the number could be higher: “I think there could be more here now than in their native range” of Southeast Asia.
I’m with Hart and other wildlife biologists tracking an 8-foot, 20-pound (2.4 meter, 9-kilo) female python that had been captured and implanted with radio transmitters a few weeks earlier.
There are many reasons why the python thrives in the Everglades, beyond the obvious fact that it eats just about anything, while almost nothing eats it.
Pythons prey on mammals, other reptiles, fish and birds. The invaders in Florida have consumed everything from the endangered Key Largo woodrat to the threatened American alligator.
Last October, a snake in the Everglades was found to have swallowed a 76-pound (34-kilo) deer. Another specimen was discovered with an adult alligator bursting from its insides -- a tooth-and-claw encounter neither animal survived.
In January, the proceedings of the National Academy of Sciences published a study showing “dramatic declines” of mammal populations in southern Florida -- raccoon, opossum, bobcat, deer and rabbit -- all believed to have become snake food.
It is not known how the Burmese python was introduced to the Everglades. Large pythons -- almost certainly escaped or discarded pets -- have been spotted here since the 1980s. By 2000, however, it was clear that the snakes were not escapees, but a growing, breeding population.
“People think this is a Florida thing,” says Ken Warren of the U.S. Fish and Wildlife Service. “But there have been reports of large constrictors found in Texas, Georgia and California, as well as the Virgin Islands and Puerto Rico. This is bigger than Florida.”
Federal agencies and local governments have spent more than $6 million since 2005 to figure out how to control the snakes. Eradicating them is not a realistic goal; managing them is imperative. To that end the biologists are gathering data.
“What we’re ultimately trying to do is understand the biology,” Hart says. “How do you exploit what you know to really knock them down? Where might the pregnant females be? What is their preferred diet? That’s the kind of information we need to design control strategies.”
Besides the python we’re tracking, there are seven other snakes implanted with transmitters, including a female weighing 140 pounds. Their movements are tracked almost daily, either on foot or from small planes.
Meanwhile, lawmakers are doing the legislative equivalent of closing the barn door after the horses have fled. Earlier this year, the U.S. House Judiciary Committee approved a bill to widen the ban on imported snakes to include the Burmese python and other large serpents.
Aside from their indiscriminate diet and unchallenged position in the food chain, Burmese pythons have other survival advantages. Hatchlings are big -- two to three feet long when they wriggle out of their eggs -- and so are not easy pickings for a potential predator. It is believed that females can reproduce without a male partner.
They are excellent swimmers, can survive for extended periods in salt water if they have to, and are barely visible in the Everglades habitat, so can sneak up on dinner with ease.
“I think she’s right between us,” the biologist next to me says. He points his antenna at my feet, which I can’t see in the murky water. Nor can I see the snake, until the slightest movement betrays her location, about a yard away.
Her head looks to be the size of my fist. Her colors aren’t brilliant but they are beautiful, a delicate patchwork of tawny lines that match the grasses all around us.
The biologists record the salient details: habitat, predominant flora, GPS coordinates, and so on. The snake doesn’t flee at our approach. For an invasive species, she looked very much at home.
(Mike Di Paola writes on preservation and the environment for Muse, the arts and culture section of Bloomberg News. The opinions expressed are his own.)
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