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. Russ Kinsman

    As the population of these animals diminish, maybe humans will be next on the menu.

    February 1, 2012 at 6:24 am | Report abuse |
  2. martha

    its jsut a shame that actual native wildlife is being wiped out by nonnative snakes...part of the problem is that people think these things are cool but when they get too big they turn around and let them go not thinking what it will do to the area and the people around it.....they need more snake hunters out there in the everglades

    February 1, 2012 at 6:46 am | Report abuse |
  3. Mike

    A big cash reward for the capture of snakes is one way to deal with this,humans will/can wipe out anything if cash is involved.

    February 1, 2012 at 7:09 am | Report abuse |
  4. gaetano

    They keep catching them but then they release them. IDIOTS. Kill the sob"s.

    February 1, 2012 at 7:13 am | Report abuse |
  5. Malcolm

    They need to start offing a yearly salary to hunt these rodents pests, something that would enable the already poverty stuck family a means for an alternative income. I would suggest hiring the local population or people that live in the bayous of louisiana, the true swamp hunters. Open up a market that focuses on pythons and start it up. Things like this just need to offer a little incentives. hunt these damn things to extinction. We've done it with the wolves and the bison, now do it with the snakes.

    February 1, 2012 at 7:21 am | Report abuse |
  6. julie

    excuse me everybody that is the least of our problems up here in citrus county there is huge lizards and I should know I was charged at 4 xs frommy shed and it tried to kill my cat this lizard was 7 feet long nile monitor lizard ok. try that for a sleeping pill some idiot dumped it and it tore my shed apart killed cats, snakes, and other animals in my shed. NOT FUNNY GUYS!

    February 1, 2012 at 7:28 am | Report abuse |
  7. julie

    you know how many eggs these things put out 20 to 30 up to 60 at a time do the math. number two does any one of you know how to handle a big snake if your constricted do you know how gps it and take girth and weight for the studies that are being donwe not as easy is that is it.

    February 1, 2012 at 7:33 am | Report abuse |
  8. julie

    these lizards a venomous they have bacteria that causes bloos poisoning the tail is a whip they have sharp teeth and when they bite you can bleed out if it hits an artery any questions!

    February 1, 2012 at 7:34 am | Report abuse |
  9. Richard Watson

    This has been going on for several years. Why don't they have a hunting season on these snakes in the spring, when they lay their eggs? That would make a severe dent in the population during breeding season and we can have a new show on the history channel, Snake people of the everglades.

    February 1, 2012 at 7:34 am | Report abuse |
  10. Fritz Hohenheim

    Why not make Snake leather boots fashionable on the shows those rednecks watch, like Ax men, Alaska Ice road truckers, Pawn Stars and other shows form the section "About the loosers in life". This way they would kill the snakes when they grow up and make a pair of cowboy boots, or maybe Cowgirl boots for their Sue Ellen.

    February 1, 2012 at 7:38 am | Report abuse |
  11. pops

    put a 100 or 200.00 dollar bounty on each one caught or harvestd

    February 1, 2012 at 7:44 am | Report abuse |
  12. 1/7th Mike

    Time for collateral damage. Start throwing and dropping stun greneade's into the water and marsh's where the snake's live. Flush them out. Utilize 12ga OOO buckshot or any type of automatic weapon fire for visual kill's. Your marsh. Your snake's. Hire me.

    February 1, 2012 at 7:54 am | Report abuse |
  13. kmhunt

    Implement a $5/head bounty? I would also think requiring anyone hunting these snakes be required to obtain a permit after taking a species identification class, to help protect native species. I'm sure Florida isn't the only place affected by these snakes, Houston seems to have a small population living in the canals.

    February 1, 2012 at 7:55 am | Report abuse |
    • aaron

      Yes, make it a sport. With big prizes for the largest animals and maybe even multiple animals by weight. And when you consider the potential tourism dollars a few "snake seasons and festivals" could generate, the state wouldn't be out any $$$.

      February 1, 2012 at 8:27 am | Report abuse |
  14. robin

    If they do not allready have a law. There needs to be strict laws and fines against dumping non native species into the wild. They need to wage war on these snakes to save the everglades. Perhaps putting a bounty on them as they did to the rattlesnakes at one time which drove them to the point of extinction but in this case we need to extinquish this invasive species. Finding their nests and destroying the eggs would be part of the strategy.

    February 1, 2012 at 8:00 am | Report abuse |
  15. Julie doesn't know how the internet works

    Dude, really?

    Now it's time yell insults at the wind and shake your fist angrily at the moon.

    February 1, 2012 at 8:35 am | Report abuse |
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