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. MAVVV

    Vote Ron Paul and eliminate this snake problem in FL and Wash DC.

    January 31, 2012 at 10:45 am | Report abuse |
  2. fearlessdude

    Registered or licenced bounty hunters would be a way to fix it. Bring them in dead.

    January 31, 2012 at 10:45 am | Report abuse |
  3. MAVVV

    U left out Muslims and fat Newt........man he would be 5 day meal for any snake. Whats a Newt......toad frog? Man that 3rd wife looks like she stuck finger in light socket and left it there little too long.

    January 31, 2012 at 10:47 am | Report abuse |
    • jb

      ^^^ Behold the enlightened Left...
      (I vote 3rd party, so you can keep the Rep barbs.)

      January 31, 2012 at 12:05 pm | Report abuse |
  4. Tom Thomas

    Feed the snakes to the homeless!

    January 31, 2012 at 10:47 am | Report abuse |
    • blablabla

      I hear they taste just like chicken

      January 31, 2012 at 12:17 pm | Report abuse |
    • Amy

      Or feed the homeless to the snakes !!! LOL

      January 31, 2012 at 5:44 pm | Report abuse |
  5. matt a.

    These exotic pets should have been banned from importation decades ago–and not just pythons.

    January 31, 2012 at 10:48 am | Report abuse |
  6. borderliner

    Who in his/her right mind will have a predator as a pet? I agree that all baby predators are cute but when they grow up and become adults they do one thing and one thing only, eat anything below their place in the food chain and that includes us, this is how nature works and has been working for the past trillion years. There should be open season all year long on those snakes until the land is clear of them.

    January 31, 2012 at 10:49 am | Report abuse |
  7. Jeff

    Feed the Republicans to these snakes :P

    January 31, 2012 at 10:50 am | Report abuse |
  8. Lila

    I will never understand why they are sold as pets. It should have been banned years ago. They grow into large out of control animals and people are so stupid they dump them into the wild.

    January 31, 2012 at 10:51 am | Report abuse |
  9. bmsadler01

    Why would anybody want a python for a pet? I thought the purpose of a pet is companionship, unconditional love...etc A large python, if given half a chance would eat you. Plus pet owners grow tired of their "awesome pet' and get rid of it in the swamps. So they couldnt have loved their pet snake that much.

    January 31, 2012 at 10:51 am | Report abuse |
  10. Lila

    I will never understand why they are sold as pets. It should have been banned years ago. They grow into large out of control animals and people just dump them into the wild.

    January 31, 2012 at 10:52 am | Report abuse |
  11. jrc

    How bout they feed you to the pythons...

    January 31, 2012 at 10:54 am | Report abuse |
  12. D Cherau

    Put a bounty on them. American colonists put a bounty on rattlesnakes in Massachusetts and the state is still free of them more than 200 years later, with the exception of two very small areas, Blue Hill in the eastern town Milton and on Mount Washington in the westernmost end of the state.

    January 31, 2012 at 10:55 am | Report abuse |
  13. Hadenufyet

    And youtube silver carp/ asain carp , yet another problem our leaders missed and let occur.

    January 31, 2012 at 10:56 am | Report abuse |
  14. Will

    These exotic pets should have been banned from importation decades ago. That goes for any exotic pets.

    January 31, 2012 at 10:57 am | Report abuse |
  15. Playjojo

    One fix, though slow, is to stop selling these things to kids, or anyone for that matter. No one NEEDS a python or exotic snake, or alligator, or big cat etc. Pet shop owners should know that when they grow, they're just going to be let loose because the population for the most part, cannot take care of them. It's hard enough dealing with the black market, they're just making it harder.

    January 31, 2012 at 10:58 am | Report abuse |
    • L

      Oh yeah brilliant. Somehow you fail to realize that these snakes are not just being released into the wild, wreaking havoc, and then dying a couple months later. They are now fully established into the environment and are breeding on their own and surviving on their own. Even if nobody else released one of these into the wild, they would still be multiplying and further damaging the ecosystem. It's explained very plainly in the article. The only thing that will stop these snakes is people going out and catching them and/or killing them on the spot.

      January 31, 2012 at 11:12 am | Report abuse |
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