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.

Other stories you might be interested in:

Hunting snakes in Florida

Tylenol-spiked mice air-dropped to kill snakes

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

    It doesn't matter if small animals are being wiped out. What matters is that idiots and morons retain the right to own wild, dangerous undomesticated animals that they can set free when they become bored with them, fearing no repercussions from our law enforcement.

    January 31, 2012 at 12:19 pm | Report abuse |
  2. george in texas

    tylon spiked rodents as a trap has worked well to control brown snakes in guam.

    January 31, 2012 at 12:20 pm | Report abuse |
  3. Joe

    Offer a reward for these snake carcasses, and they'll be hunted to extinction within a month.

    January 31, 2012 at 12:26 pm | Report abuse |
  4. Rusty

    It is speeled It, not Ilt. LOL

    January 31, 2012 at 12:27 pm | Report abuse |
  5. Grumpster

    We need to get those "Swamp People" they show on TV who go after gators to take up a new hobby in the glades...and put a bounty on pythons so they can go in and do what they do best. Hunt the rascals and be enthusiastic about it.

    January 31, 2012 at 12:27 pm | Report abuse |
  6. CharlieMike

    Thes snakes make great boots, let the unimployed hunt them down and sell them for profit. That will wipe out the snake problem. Take a problem, find how to make money off of it, works every time.

    January 31, 2012 at 12:28 pm | Report abuse |
    • Barry

      Actually one of the only smart comments in this blog,,,great idea

      January 31, 2012 at 12:32 pm | Report abuse |
    • brilliant

      I love it when idiots offer advice on fixing things. Are you imployed anywhere?

      January 31, 2012 at 12:38 pm | Report abuse |
  7. red1

    Would you feel bad if you jumped someone for making a comment like "use a big net" only to find the comment was made by a 10yr old tring to add their voice? Oh and why are the things people do not considered "acts of nature"? Whatever we do is "natural". Everything we do that affects this planet is natural. We are animals too. We are a force of nature just like the weather. And to point out misspellings is assine. Spelling words wrong doesn't show your education level! You just forgot to hit "spell check". There are some mean mother*#%er's that blog

    January 31, 2012 at 12:30 pm | Report abuse |
    • nepawoods

      "... you represent that you are 13 years of age or older and, if you are under the age of 18, you either are an emancipated minor, or have obtained the legal consent of your parent or legal guardian to enter into these Terms of Service, submit content, participate on CNN.com, and fulfill the obligations set forth in these Terms of Service, which forms a binding contract between you and CNN"

      January 31, 2012 at 12:36 pm | Report abuse |
  8. RAMBLE3144

    It's a real positive effect of Obama's Stimulus program!

    January 31, 2012 at 12:30 pm | Report abuse |
    • So...

      Since you've brought politics into this...

      The Obama administration has actually moved on new regulations meant to limit the damage wrought by these snakes, finalizing a rule making it illegal to import or move Burmese pythons across state lines. House Republicans, notably, derided this regulation as damaging to small businesses and job creation, going so far as to bring a snake breeder to testify before the House Oversight and Government Reform Committee, who said the rule could “devastate a small but thriving sector of the economy.” A House Republican report even derided the regulation as “a solution in search of a problem.” Well it looks to me like there IS a problem... a big one

      January 31, 2012 at 12:39 pm | Report abuse |
  9. Barry

    All stupid comments aside, at least one person mentioned a reward for killing the snake, which is a great idea.

    January 31, 2012 at 12:30 pm | Report abuse |
    • Grumpster

      Another job for the illegals. Plenty down there with nothing to do.

      January 31, 2012 at 12:33 pm | Report abuse |
  10. Linann

    Don't blame the snake. Humans have been killing the Earth for a very long time.

    January 31, 2012 at 12:33 pm | Report abuse |
  11. sierrafoxtrot66

    Hunt them – yes, bounty for each – yes...and then? It was stated that:

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

    SO send the meaty beasts to Southeast Asia to help mitigate the issue there, more of a global solution.

    January 31, 2012 at 12:33 pm | Report abuse |
  12. bezerkur

    i meant the pythons. not gators. Actually I think that show swamp people is repulsive. They kill the biggest alligators which some are probably 60-100 years old and no doubt effect the natural eco-system. I would think them swamp people who make a living killing gators would want to hunt the snakes.

    January 31, 2012 at 12:36 pm | Report abuse |
  13. harrison

    Huntin season, bet python skin goes for a pretty good price

    January 31, 2012 at 12:38 pm | Report abuse |
  14. nepawoods

    You can't fix this problem by hunting them. For every big one you can find, there will be hundreds of little ones hiding under rocks and logs. How many released pets do you think it took to start this problem? Far, far less than all the little ones that would be left behind to reproduce no matter how much hunting is done.

    Not that hunting wouldn't be good, just to make use of the meat and skins.

    January 31, 2012 at 12:41 pm | Report abuse |
  15. Barney Rubble

    Simple......open snake season. Python makes nice boots, purses, and belts. Plus the left-over meat can be fed to the illegal Mexicans and welfare blacks who vote for Obama. Win- Win situation.

    January 31, 2012 at 12:44 pm | Report abuse |
    • t

      this is sorry talk... my goodness...

      January 31, 2012 at 12:52 pm | Report abuse |
    • Liqmaticus

      Racist much?

      January 31, 2012 at 12:55 pm | Report abuse |
    • kadaf legacy

      men u need to grow God hate racist

      January 31, 2012 at 12:55 pm | Report abuse |
    • Grumpster

      we atheists don't like it much either...

      January 31, 2012 at 12:58 pm | Report abuse |
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