Pythons wiping out mammals in Everglades, researchers say
A Burmese python in the Everglades swallowed a 76-pound deer last year.
January 31st, 2012
09:34 AM ET

Pythons wiping out mammals in Everglades, researchers say

Burmese pythons have eaten so many small mammals in Everglades National Park that populations of rabbits and foxes have disappeared and numbers of raccoons, opossums and bobcats have dropped as much as 99%, according to a report released Tuesday by researchers at Virginia Tech University, Davidson College and the U.S. Geological Survey.

“Pythons are wreaking havoc on one of America’s most beautiful, treasured, and naturally bountiful ecosystems,” said U.S. Geological Survey Director Marci McNutt in a statement.

The massive nonnative snakes have become an established species in the park in the past 11 years, after snakes that were once pets were released into the wild, according to the researchers. Park spokeswoman Linda Friar said earlier this month that there are tens of thousands of the snakes in the park.

In the remote southernmost regions of the 1.5 million-acre national park, researchers could find no marsh or cottontail rabbits or foxes. In those same areas, the raccoon population has declined 99.3%, the opossum population 98.9%, and the bobcat population 87.5%, the researchers reported.

Those animals are often found in the stomachs of Burmese pythons captured in the Everglades, the researchers said.

“The magnitude of these declines underscores the apparent incredible density of pythons in Everglades National Park,” said lead author Michael Dorcas, a biology professor at Davidson College in North Carolina.

To measure the population declines, researchers traveled more than 39,000 miles at night along roads in the park between 2003 and 2011, counting both live animals and road kills. Their data were compared to similar counts made along the same roads in 1996 and 1997, before the Burmese pythons had become an established species in the park.

In northern areas of the park, where python populations have not become established, the researchers found similar mammal numbers between their recent and older surveys. But in the area where the pythons have recently become established, the researches reported a noticeable decline in mammal numbers. They called for action before the pythons wipe out mammals in the entire park.

“Right now, the only hope to halt further python invasion into new areas is swift, decisive, and deliberate human action,” McNutt said.

Burmese pythons are native to southeast Asia, their range extending from southern China to the Malay Archipelago, according to the National Zoo. The snakes reach breeding age in four to five years and a female lays an average of 35 eggs during the spring breeding season, though one snake may lay up to 100. Burmese pythons can live as long as 30 years.

In their native range, the snakes are considered threatened and are hunted by humans for their meat and skins, according to the National Zoo.

They may grow up to 22 feet long but average about 16 feet. The snakes can swallow whole animals four or five times the size of their head. In the Everglades, the pythons have been found to eat deer and even alligators.

While the researchers are concerned about the fate of the raccoons and the opossums, they say they may not even be able to measure the snakes' effect on more elusive species.

“Such severe declines in easily seen mammals bode poorly for the many species of conservation concern that are more difficult to sample but that may also be vulnerable to python predation,” Dorcas said in a statement.

The researchers compared the proliferation of pythons in Florida to that of the brown tree snake on the Pacific island of Guam, where native species have disappeared since the introduction of the snakes. But they said it's happening faster in Florida.

“It took 30 years for the brown tree snake to be implicated in the nearly complete disappearance of mammals and birds on Guam; it has apparently taken only 11 years since pythons were recognized as being established in the Everglades for researchers to implicate pythons in the same kind of severe mammal declines,” U.S. Geological Survey scientist Robert Reed said in the report.

Earlier this month, the U.S. Fish and Wildlife Service instituted a ban on the importation of the Burmese python and three other nonnative constrictor snakes - the yellow anaconda and northern and southern African pythons.

But the researchers say they'll still need to do more.

“This severe decline in mammals is of significant concern to the overall health of the park’s large and complex ecosystem,” Everglades National Park Superintendent Dan Kimball said in a statement. “We will continue to enhance our efforts to control and manage the non-native python and to better understand the impacts on the park.”

The latest research was published this week in the Proceedings of the National Academy of Sciences.

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Filed under: Animals • Florida • Snakes
soundoff (456 Responses)
  1. Azr43l

    Just look at the type of people that own constrictor type snakes. Trashy. Which is exactly what Florida is full of – trailer trash. Not at all surprised all these former "pets" are getting dumped by the morons that originally acquired them. Who in their right mind thinks having an anaconda as a pet is a good idea or even possible???

    January 31, 2012 at 12:49 pm | Report abuse |
  2. leeintulsa

    you realize black welfare recepients generally live in the large cities.. the rest of the country is filled with poor white folks on welfare.. right? there are far more whites on welfare than blacks? that's why their called a minority..

    January 31, 2012 at 12:49 pm | Report abuse |
  3. Boodrow

    Florida should have a shoot on sight, no license required on these snakes.

    January 31, 2012 at 12:49 pm | Report abuse |
    • Liqmaticus

      They're goooood eatin too.

      January 31, 2012 at 12:54 pm | Report abuse |
    • Aeromechanic

      They do. No license is required for non-native species.

      January 31, 2012 at 2:44 pm | Report abuse |
  4. bobcat (in a hat) ©

    I guess I need to stay clear of the everglades.

    January 31, 2012 at 12:50 pm | Report abuse |
  5. Dani

    You can all joke, but this is a serious problem. Read "And No Birds Sing" – the brown snake decimated the mammal and bird population on Guam. It hangs from power lines and cuts off the electrical. It messes up sewers and cuts off plumbing. It has been found in toilets, cribs, beds, and more. Those of you joking, ask yourself what is going to happen when they have decimated the mammal and bird population of the Everglades. If you live in the south where the python is comfortable with the temperatures–then it is going to start migrating to where its food sources are–the coast and then North in the southern states where it will continue its path of destruction.

    January 31, 2012 at 12:50 pm | Report abuse |
    • t

      you are so right.... when these snakes have eaten all the viable food source available to them.. then they will naturally follow the food source... humans...

      January 31, 2012 at 12:53 pm | Report abuse |
    • Foodster

      MMM...Soylent Green.

      January 31, 2012 at 1:00 pm | Report abuse |
  6. t

    how many missing people are there due to being eaten by these things...missing children.... etc... they should kill as many of these snakes as possible... no one should have even been allowed to purchase one of these...way back when... My neighbor told me once... if she could look in my back yard because her pet snake got loose.... yeah hers was a medium size snake at the time. and it's like anything else... everything gets out of hand... like our American borders... nobody does nothing until ithe problem becomes huge....

    January 31, 2012 at 12:50 pm | Report abuse |
  7. Taioseach7

    If you used the internet for more than just stroking your ignorance you'd discover that there are more caucasians on welfare than minorities.

    Why don't you take a walk through the everglades one night? Be sure to wear a blindfold.

    January 31, 2012 at 12:51 pm | Report abuse |
  8. W.G.

    Why not have snake hunts with Cash Prizes ! Sponcers donate cash and collect the skins for boots !
    All sizes included no minimum sizes that shoul end the problem . Tell the contestanst what snake are
    eligable and see how fast the python population goes down ! Money Talks B.S. Walks .

    January 31, 2012 at 12:51 pm | Report abuse |
  9. thetruth

    lets feed them your mother so she won't inbreed another hill billy like you .. and what's up with ppl thinking it's more black ppl on welfare than whites?? what rock have you been hiding under?? you need to read a book and educate your self because it clearly more white ppl on everything than blacks because whites make up the greater population in america.. who teaches you guys this crap??

    January 31, 2012 at 12:52 pm | Report abuse |
  10. brian

    CNN needs to screen offensive posts.

    January 31, 2012 at 12:53 pm | Report abuse |
  11. Liqmaticus

    The dinosaurs are retaking Earth!

    January 31, 2012 at 12:53 pm | Report abuse |
  12. Jeff Lebowski

    Idiots with pet snakes. Why the hell would you keep a snake in a glass box? Beyond dumb. Add in pet rats, gerbils, mice, hamsters, lizards, turtles, etc. They don't belong in tanks!

    January 31, 2012 at 12:56 pm | Report abuse |
  13. helicohunter

    Time for someone to invent a good snake trap. Maybe a caged rabbit surrounded by an enclosure with a snake-sized hole. Two sensors to select for a long animal (not mice, rats, etc.). Connect them to a guillotine. The snake gets killed and the rabbit is unharmed.

    January 31, 2012 at 12:57 pm | Report abuse |
  14. warm in Alaska

    Dolt !

    January 31, 2012 at 12:58 pm | Report abuse |
  15. Joe R.

    "In their native range, the snakes are considered threatened and are hunted by humans for their meat and skins, according to the National Zoo."

    Anyone have some good recipes for Python meat? Florida can start serving it, in addition to the gator meat they've served for years. Then you can start seeing python bags and python shoes. Oh wait, PETA might throw a fit. Oh wait, who cares about PETA anyway?!

    January 31, 2012 at 1:00 pm | Report abuse |
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