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. lt_murgen

    I agree with year round open season and bounties. – Pythons and feral pigs.

    Look at what we did to the buffalo populations in just 30 or so years. Took them down from uncounted millions to an endangered species.

    Conservationist hunters are one of the best ways to control any animal population. Working in lock-step with the local Fish and Wildlife authorities, they could bring the population under control.

    January 31, 2012 at 11:16 am | Report abuse |
    • Bookenz

      They should do more than bring them under control – the species should be eradicated since they're non-native to the area.

      January 31, 2012 at 11:34 am | Report abuse |
    • STEVE

      Comparing the hunting of Bison to pythons is like comparing a high school student to a doctor, When the Bison were hunted they traveled in large herds on the plains. Where a python is a solitary animal living in the glades able to conceal itself in a variety of areas within the Glades. When hunting Bison hunters had no problem spotting a herd miles away just by the dust and noise created by the mass movement of large herd, no such luck with a python moving through the grasses, reeds or waters of the glades.

      January 31, 2012 at 3:56 pm | Report abuse |
  2. Mike

    Use Rabbits. Mount GPS tracking devices on them with an alarm that sends a signal when they are swallowed or die. Then follow the GPS coordinates right to the snakes and destroy them (if eaten by gators or other predators you can just let em poop it out). Selectively breed small, slow moving rabbits then attach the device and let them go all over Florida. The devices should be reusable. Put a bounty on them as well.

    January 31, 2012 at 11:16 am | Report abuse |
    • Bookenz

      With laser beams in their eyes.

      January 31, 2012 at 11:35 am | Report abuse |
    • Michael Vick

      Why mount rabbits with expensive GPS when you can arm it with cheap bomb? If python eats it that will be its last meal.

      January 31, 2012 at 12:06 pm | Report abuse |
  3. Debra

    This situation has been know about for a very long time and nothing much has been done about it. Can't a large net be placed into the water or where they live, scooped up and then killed? The only time they will get serious about this situation is when a human, like a child, is taken by one of them!!! There always has to be some kind of tragedy happen before a remedy is realized and put into never fails to amaze me. They have their conferences and talk, talk, talk but nothing is done until it is too late. It's just a matter of time...they know the consequences of doing nothing. Get moving people!!!

    January 31, 2012 at 11:17 am | Report abuse |
    • Soporifix

      The Everglades is very big. You can't put a net around it.

      January 31, 2012 at 11:33 am | Report abuse |
    • Chris R

      How do you make a net that only catches pythons?

      January 31, 2012 at 12:02 pm | Report abuse |
  4. Marty

    Humans are killing species off everyday, lets just start killing them...
    Let the snakes do their thing.

    January 31, 2012 at 11:17 am | Report abuse |
    • buck chicken

      Your missing the point. Humans F' ed it up by releasing non-native species into that ecosystem. Now there are no natural predators to keep the pythons in check. since we humans screwed up, again, we have to correct it so that the ecosytem is balanced.

      January 31, 2012 at 11:26 am | Report abuse |
  5. oldman100

    if we can wipe out millions upon millions of buffalo, we should be able to wipe these out as well. to hell with peta.

    January 31, 2012 at 11:19 am | Report abuse |
  6. us1776

    And once these pythons finish off all the mammals in the Everglades they'll be heading for a neighborhood near you Floridians. These huge snakes will be coming after pets and small children next.


    January 31, 2012 at 11:21 am | Report abuse |
    • us1776

      If one of these huge snakes bites you and gets a good grip, you're a goner.

      It's only a matter of time before they'll get a coil around you and crush you to death.


      January 31, 2012 at 11:33 am | Report abuse |
  7. annmartina

    This probably isn't just from people releasing pets. Supposedly masses of snakes escaped when reptile warehouses were destroyed in Hurricane Andrew. I wonder how python tastes?

    January 31, 2012 at 11:24 am | Report abuse |
    • Rob Vukovic

      When the pythons run out of varmint burgers, they'll be wondering how humans taste.

      January 31, 2012 at 11:39 am | Report abuse |
  8. Pedro

    This is what happens when a nonnative species invades the US.

    January 31, 2012 at 11:24 am | Report abuse |
  9. Juan the subcontractor

    This also happens when nonnative species invade.

    January 31, 2012 at 11:27 am | Report abuse |
  10. Dixie Normous

    Two words....Honey Badger

    January 31, 2012 at 11:28 am | Report abuse |
  11. Dallas

    Collecting one snake here and there is not cutting it. These snakes need to be killed and trapped in large enough cages to remove them. It's disturbing how slow everyone is handling this crisis and all the new born animals are being wiped out before even having a chance at life. This needs to be done in a massive effort over and over to control and bring the Everglades back to their natural beauty.

    January 31, 2012 at 11:30 am | Report abuse |
    • A.H.H.

      I'm scared of what happens when these things run out of food! Do they then go into the cities and eat kids and pets? Or move north? Yikes! I'm going to have nightmares.

      January 31, 2012 at 11:43 am | Report abuse |
    • Chris R

      How do you expect to have traps that only catch Burmese pythons? Look, they are doing what they can but the hunt has to be done by people on the ground. It way be worthwhile to open up hunting on them and find a market for their meat and skins. The sad truth is that government resources are stretched thin already and dedicating more tax payer money to this hunt would probably not go over well.

      January 31, 2012 at 11:49 am | Report abuse |
  12. Jim P.

    Why not have a sanctioned hunt or offer trappers a bounty? There is an annual gator hunt in the everglades and this is a much more pressing issue to preserve the everglades

    January 31, 2012 at 11:33 am | Report abuse |
  13. ideamaker

    Start eating them. Snake meat is just as good as anything else.

    January 31, 2012 at 11:34 am | Report abuse |
  14. bigaltro

    Start the barbecue and the deep fryer...Python its whats for dinner.

    January 31, 2012 at 11:37 am | Report abuse |
  15. Mark

    Why do these WT hicks keep reptiles as pets? Reptiles have no capacity for emotion, are predatory carnivores, have no functional value (e.g. – like a dog or a horse) and have no place in one's home. What? Does it make you seem like you're a bad-a55 by having one of these around your house? Grow up! They should feed any dolt who keeps a reptile to these snakes.

    January 31, 2012 at 11:37 am | Report abuse |
    • Jim

      because these nitwits need something to seperate them from everyone affirm their inner voice that says to them..."I am so amazing".

      January 31, 2012 at 11:58 am | Report abuse |
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