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Congress weighs ban on importation of pet pythons

Prompt action is needed at the federal level to limit the number of invasive pythons released into the wild, South Florida Water Management District (SFWMD) Deputy Executive Director George Horne said in written testimony to the U.S. Congress today.

The House of Representatives Subcommittee on Crime, Terrorism and Homeland Security is considering a Bill that would classify nonnative pythons, such as the Burmese python, as “injurious animals” and ban their importation into the United States.


Hypothetical diet necessary for a hatchling Burmese python to reach 13 feet in the Florida Everglades (approximately 5 to 7 years)

1 raccoon
1 oppossum
4 five-foot alligators
5 American coots
6 little blue herons
8 ibises
10 squirrels
15 rabbits
15 wrens
30 cotton rats
72 mice

This illustration and the photos on this page were appended to the SFWMD written testimony handed to Congress today.

(Source: Skip Snow, Everglades National Park & Dr. Stephen Secor, University of Alabama)

“As a top predator and prolific breeder, these exotic snakes threaten state and federal efforts to restore America’s Everglades, and they prey on the natural wildlife that call the Everglades home, including species already threatened or endangered,” SFWMD’s Horne said in the agency’s testimony to Congress.

“We have a long history of successful invasive plant management and experience, but only recently have we had to commit more and more resources to the emerging populations of the Burmese python and other nonnative constrictors appearing across our landscape.


“If effective preventative programs were in place to limit introductions of nonnative constrictors, such as the legislation now under consideration, these much-needed taxpayerfunded resources could be redirected to other important resource management efforts.

“Today, however, the negative impacts from the unlimited importation of new pest animals require active responses on our part. Effective prevention of additional introductions of potentially invasive constrictor snakes, as proposed in this Bill, is the only path to prevent these costs from continually increasing.”

While Florida, California and Hawaii are among the states most impacted by introduced invasive species, every state is affected, Horne added.

Photo of Burmese python killed in Florida courtesy of SFWMD

“Globally, exotic invasive species, including pest animals, weeds and pathogenic diseases, are a major cause of global biodiversity decline. In particular, nonnative animals compete for food and habitat, upset existing predator/prey relationships, degrade environmental quality, spread diseases and, in our case, may threaten the integrity of flood protection levees and canal banks, and electrical power delivery.

“Nationally, more than 50,000 species of introduced plants, animals and microbes cause more than $120 billion in damages and control costs each year. Already, 192 nonnative animal species are established in Florida, calling for the development of methods to forecast and respond to the potential economic loss, environmental damage and social stress caused by both new nonnative animal introductions and long-established invasive organisms,” Horne said.


The Bill before Congress makes an important contribution towards prevention by limiting the importation of two snake species (the Burmese and African pythons) with high invasion potentials in the U.S., Horne said.

“The amendment could also be expanded to include all giant constrictor species determined by the U.S. Geological Survey (USGS) to have medium or high invasion risk potential. The recently published USGS risk assessment for giant constrictors ranked nine species as having either a medium or high overall risk potential for invasion in the United States.

“These species include the Beni Anaconda, boa constrictor, Burmese python, DeSchauensee’s anaconda, green anaconda, northern African python, southern African python, reticulated python, and yellow anaconda.”

Photo of Burmese python killed in Florida courtesy of SFWMD

“We strongly support inclusion of these species in [the Bill] in order to immediately limit importation of species that our best science predicts will be invasive,” Horne added.

“Rather than wait for the next Burmese python to become established in the United States, a proactive approach such as the proposed legislation being discussed today is urgently needed to protect our environment, economy and quality of life–not just in Florida but throughout the nation.”

The South Florida Water Management District is deeply committed to preserving and restoring South Florida’s environmental health and, unfortunately, the Everglades ecosystem is now home to the invasive Burmese python, Horne said.


Fifty-two eggs were inside a 16-foot Burmese python found in May, 2009 by South Florida Water Management District officials south of the Tamiami Trail in Miami-Dade County, Florida.

Photo courtesy of SFWMD

The snake is a top predator that is known to prey upon more than 20 native Florida species. Notable among these are the federally listed Key Largo wood rat, white-tailed deer, American alligator, bobcat and numerous wading birds common to the Everglades, including the wood stork.

“Attempts to manage Burmese pythons divert taxpayers’ funds from these other urgent primary restoration and protection tasks. Yet, failure to do so will leave this aggressive animal as a serious impediment to our Everglades restoration progress,” Horne said.

Small livestock likely prey

The Burmese python also threatens agricultural interests as small livestock are also likely prey, Horne added.

Since 2000, the South Florida Water Management District and Everglades National Park have removed 1,248 Burmese pythons from the Everglades.

“Experience already gained in Florida strongly indicates the need to regulate the importation and sale of this snake. Without stronger regulation and control resources, adverse impacts of Burmese pythons will continue to get worse, and the python’s population will continue to expand north of the Everglades and likely into South
Florida’s urban areas.”


Burmese python nest eggs found in Miami-Dade County in Florida

Photo courtesy of SFWMD

Florida’s other nonnative giant constrictors

Given South Florida’s abrupt boundaries between dense human population centers and vast subtropical wilderness areas, it comes as no surprise that numerous giant constrictor species have been observed in Florida, Horne said.

“While most observed animals are presumed to be released pets, three additional constrictor species are now considered established or potentially established in Florida–the common boa, northern African python and yellow anaconda.

“All three species are identified in the USGS risk assessment as having a high overall risk of establishment in the
United States. The common boa has been repeatedly observed in South Florida, primarily on the Deering Estate in eastern Miami-Dade County, but also near Everglades National Park.

“Between 1989 and 2005, 96 common boas were captured in South Florida.

“Recent confirmed sightings of northern African pythons near the eastern boundary of the Everglades and yellow anacondas near Big Cypress National Preserve and Myakka State Park in southwest Florida are also cause for alarm.”

“Recent confirmed sightings of northern African pythons near the eastern boundary of the Everglades and yellow anacondas near Big Cypress National Preserve and Myakka State Park in southwest Florida are also cause for alarm. All three of these species share traits with the Burmese python that are considered important factors for invasive potential, and like the Burmese python all three species will be very costly to control should they become widely established.”


Burmese python photo courtesy of South Florida Water Management District

As the South Florida Water Management District and other agencies try to contain the documented damage and growing threat of the Burmese python and other invasive animals in Florida, the flow of potentially harmful exotic animals across U.S. borders continues, Horne said.

“To use just one example, roughly 144,000 boa constrictors were imported into the United States between
2000 and 2007. Federal action is needed now to address the immediate threat posed by giant constrictors which have or are likely to establish in our nation’s wilderness areas.”


This map from the recently published USGS risk assessment for giant constrictors suggests how much of the United States has a climate suitable (green area) for the establishment of the Burmese python.

Map courtesy of USGS

You might also be interested in:

“National Geographic Explorer: Python Wars” airs in the United States on February 9, at 10 p.m. on National Geographic Channel. Click on the video above to watch an excerpt. Click here to view more excerpts and get additional information.

Reptile owners weigh in on invasive snake issue
The people who say they know most about boas and pythons, the pet reptile owners and traders, have different perspectives about what’s needed to prevent and reverse the problem of the snakes breeding in the wild.


100-pound albino python seized from Florida Panhandle home
In the latest crackdown on nonnative giant pet snakes in Florida, Fish and Wildlife Conservation Commission (FWC) investigators have confiscated an 11-foot, albino Burmese python living uncaged in a private residence.


Nine giant invasive snake species threaten U.S. ecosystems, study finds
Giant nonnative snake species would pose high risks to the health of ecosystems in the United States should they become established in the country, the U.S. Geological Survey (USGS) says in a report.


Pythons in Florida: Who are you Going to Call?
Florida Fish and Wildlife Conservation Commission appeals to residents of the state to report wildlife law violations. FWC also hosts amnesty days for people to turn over for placement giant snakes they can no longer keep as pets.


Pythons in Florida Everglades: Is the Snake Invasion Only Beginning?
The giant snakes were imported to North America as pets, but released or escaped into Florida’s wetlands they are proliferating, challenging alligators for the top of the food chain, and potentially positioning themselves to invade much more of the United States. Conservation biologist Stuart Pimm discusses the problem.


  1. Tim Livera
    North FL
    April 27, 2013, 2:10 am

    As a resident of Florida, and former resident of Arizona, I have seen the survival capabilities of different reptiles in captivity and free in nature. Every living creature has survival instinct of course and only certain climates will sustain certain species for a period of time. However, regardless of their survivability or procreation ability, if a species is not indigenous to the region that it inhabits, it becomes a detriment to the ecosystem of that region. With that, every species has a purpose in it’s natural environment. With that, “where there is a will, there is a way.”. In time, nature never ceases to press beyond the scientific theories and laws of physics to evolve seemingly any species. Who really care’s about a mapping projection of possible climate sustainability regions for a nonindigenous species to eventually populate? Isolated incidences are inevitable simply by the introduction of the species in relative proximity to the region(s). If the unnaturally placed occupants overpopulate the region, they will alter the ecosystem until eventually exhausting the sustainability resources. At which point, survival instinct will drive them beyond their natural environment; thus the evolution of a species. Argue all of the scientific studies and proven theories you want. With time nature continues to provide living examples disproving those arguments. This problem didn’t occur overnight obviously, and the solution will be a large undertaking. I’m not politically savvy, however it seems that federal funding can be spent any number of ways regardless of the actual benefit. I say do whatever it takes; “wipe em out”; all of them. Outlaw personal possession and require permanent registry, via UID chip, for every one imported for commercial use to be documented and audited for the entire lifecycle. In time, it may become a decision of “Us or Them”. We are still the most advanced life forms on the planet correct? Why is it that we can’t solve the very problems we create? Ah yes, politics. Perhaps we’re not that advanced after all. At some point someone needs to be willing to look beyond the financial impacts of growing problems to create solutions. Allocating federal funding as it has been, for especially the last five years, seems extremely inappropriate and ineffective in some cases, to say the least. Solving the financial problems of multibillion dollar corporations or “stimulating” the economy with checks for all registered taxpayers, only to raise tax collection rates in order to compensate, served absolutely no purpose at all. Real problems become financial problems, and financial problems become more financial problems until the real problems are overshadowed and under addressed. That’s politics and that’s how I see it. Focused attention, toward actual problems that are not based on finance alone, will create change in the US economy. Real change. C’mon Man! Get with it! I didn’t have to get a college degree to figure that. I’m a taxpaying US citizen, and I endorse this message. ; )

  2. Graham
    February 4, 2012, 4:18 pm

    That map is the biggest piece of misinformation I’ve ever seen! Pythons are a tropical species, the entirety of the continental US, except for the very southern tip of Florida, is temperate. They would not survive any further north. In fact, a group of scientists conducted an experiment with 10 Burmese pythons by keeping them outdoors in a secured enclosure all year. None of them survived the winter, it’s simply too cold for them.

    If that isn’t enough evidence, allow me to provide a native plant species that I have plenty of experience with to demonstrate why they won’t be able to survive outside of sub-tropical FL. There’s a genus of pitcher plants that is normally found in the southeast of the US, except for the northen populations of Sarracenia purpurea. These plants require a cold winter dormancy to live. This has kept them from inhabiting the southern part of FL, where the pythons, and many other non-native species have invaded. This classifies these amazing plants as temperate. Pythons are tropical, and cold blooded. Saying that they can invade into areas where Sarracenia inhabit is false. Sarracenia flava reaches its northern most limit on Southeast VA, where the map says pythons can invade. If a group Southeast temperate species that is NATIVE to North America can’t even live that far north I doubt a tropical species will.
    Yes, I am an artist, but clearly I can do better research than the author.

    Also, this map was drawn up PETA and HSUS, which we all know use faulty information for their propaganda and blatantly lie about their policies.

    I have photographed a lot of large reptiles in the past few yours without a dividing barrier and I can tell you they are not dangerous to people if they don’t feel threatened. In fact, horses killed hundreds more people than every pet snake in the US combined in the past two years.

    National Geographic, this article greatly disappoints me. Your publications are usually good sources of information, but this one is terrible!

  3. Husker
    June 21, 2010, 11:13 pm

    “As a top predator and prolific breeder, these exotic snakes threaten state and federal efforts to restore America’s Everglades, and they prey on the natural wildlife that call the Everglades home, including species already threatened or endangered,” SFWMD’s Horne said in the agency’s testimony to Congress.

  4. David Braun
    November 10, 2009, 10:47 am

    Your comments are valuable additions to the debate. I have reviewed the evidence of Mr. Wyatt to the Congress and posted a report at http://blogs.nationalgeographic.com/blogs/news/chiefeditor/2009/11/reptile-owners-on-invasive-snakes-issue.html

  5. dangles
    November 10, 2009, 10:41 am

    I thank you, Mr. Braun for taking our comments into consideration, but what upsets me so much – even more so, now that I know you had good information all along (the blog entry you linked to) – is that, even in light of that more accurate and fair report, you still write as if this ‘invasion’ is an imminent event, and that congress should act accordingly with (in this case) sweeping legislation to ban the ‘big 9.’
    I am not here to tell you the burmese python is not a problem in the Everglades; that has been well documented. I AM here to tell you that it is NOT something the rest of the nation needs to suffer for.
    I am ALSO here to tell you that this is not the result of irresponsible keepers releasing their pets into wild. The article posted by Levelhead does a much better job at explaining that than I could, so I will defer to it.
    It’s articles such as this that give further credibility to the faulty and biased reports thrust in the public’s face by the USGS. Now people can say, “look, even NatGeo says we need to do this.”
    I hope I am not coming off as rude or overly harsh, but the future of my hobby and the careers of many people I know are in SERIOUS jeopardy as a result of the (seriously) flawed USGS reports, and as you are aware – based on the other report you wrote about in August of last year – that does not have to be so.
    If more people in positions such as yourself stood up and said, “wait a minute, folks, the information you’re using to justify this legislation is flawed. Let’s take a closer look at this before we decimate an entire industry,” we may not be in the precarious position we now find ourselves in.
    So I urge you to take a closer look at the evidence we have presented you. With he help of National Geographic, we may actually be able to begin a true, balanced dialogue that would help bring about a better solution to Florida’s situation than a nationwide ban.
    I thank you again for engaging us in this conversation, Mr. Braun.

  6. Daniel
    November 10, 2009, 10:35 am

    This USGS climate map that shows how the burmese python and other tropical species might invade the USA is extremely faulty as it is only a climate map. To use this as the sole criteria for an invasion of large constrictors is about as logical as using the same map for an invasion of penguins coming from the north. Or heaven forbid the invasion of the canadian polar bears looking for new prey items.
    Yes indeed when you use professional scientists who are experts in geology to do a report on herpertology no doubt they might get some conclusions incorrect.
    How would banning the further import of these reptiles do anything at all for the already existing problem of invasive species in the Florida everglades. Take into consideration the entire problem started from hurricane Andrew 20 + years ago releasrsing the originating founding burmese pythons into the everglades not pet owners.
    How would restricting trade in large constrictors thousands of miles away from the everglades do anything for a problem in the everglades as HR 2811 would do .
    If you owned any of these species and was transferred from your current employment to another state you by this regulation could not move the species listed what then?? There are millions of these species being bred and exported to other parts of the world from the USA that would come to a stop with this law. Another big blow to the shipping companies in a poor economy.

  7. aceace88
    November 10, 2009, 12:52 am

    I would like to echo the simple solution, proposed by David G. Barker and Tracy M. Barker, to the entire exotic species problem in Florida:
    “Is there any action that might prevent still more species of plants and animals from establishing in South
    Yes, there is one very practical solution.
    Miami is the primary American port of entry for imported plants and animals, especially tropical plants and animals. Because of this, Miami is full of and surrounded by wholesalers and distributors of exotic plants and animals. At any given time, an inventory of exotic plants and animals with a cumulative value in the hundreds of millions of dollars can be found in Miami. Florida has made a lot of money from the importation business. Every shipment, every box, is stamped and cleared by USFWS, Customs, and for some cargo, even USDA.
    Some plants and animals come into the port and are nearly immediately shipped on to other destinations in the United States. Others, including exotic trees, fruits, palms, cycads, vegetables, ornamental shrubberies, exotic grasses, reptiles, mammals, birds, and tropical fish are maintained in South Florida for commercial propagation, agriculture, and captive breeding. Miami is seething with exotic species.
    The problem is that South Florida has the most tropical climate in the continental United States. Many species of escaped plants and animals thrive outside the nurseries and cages of the distributors and wholesalers. Released
    and breeding in South Florida are literally thousands of species that can survive nowhere else in the United States. And it’s all because Miami is the port of entry.
    The solution is to remove the status of the Port of Miami as an agricultural port and a port of entry. Move the port
    of entry north, maybe to one of the New England ports.
    If Senator Nelson really believes that exotic species are a terrible problem and if he wants to remove the chance of
    future introduction of snakes or any other exotic species into his beloved Everglades, then his choice is clear. As
    the Senator from Florida, he needs to spearhead a political movement to stop the importation of more exotic plants
    and animals into the Port of Miami. For the sake of nature and on behalf of the environmentalists, he needs to move this lucrative business out of his state to a place where the chance of alien invasion is minimized.
    It isn’t going to happen. It would cost Miami and Florida too much money and too many jobs. But is it a better strategy to attack the rights of hundreds of thousands of American snake owners, destroy thousands of successful American small businesses, and give millions of tax dollars to the invasive-snake biologists?”
    Does National Geographic dare to print this simple solution?

  8. MLynch
    November 9, 2009, 11:37 pm

    Why wasn’t this an issue 20 years ago? Or even 10 years ago? The answer: because it never was an issue. The reptiles that the USGS seeks to eliminate from the pet trade have been residing in households across the United States for decades and have never established a foot hold in any of the projected ecosystems, with the exception of only a couple of very small pockets. If the scenario put forth by the USGS were at all accurate residents of Washington DC; Richmond, VA; Bethesda, MD, Lawton, OK; Phoenix, AZ; and San Bernardino, CA would already be facing an ecological disaster as a result of these “invasive species.” …yet, oddly they are not.
    This report is based more on media spurred paranoia, ignorance, and prejudice than actual scientific fact. …And at what time did National Geographic stop caring about research? Had NatGeo actually looked at the situation in the Florida Everglades, studied it, as well as studied the 9 snakes the USGS is targeting the USGS report would have been found to be severely flawed.
    And something the USGS report fails to address is how eliminating these snakes from the pet trade will have any benefit to the situation in the Everglades. Why? Because it won’t. The problems faced in the Everglades will remain. The USGS has also stated that these snakes are moving north at a rate of about 1.5 miles a day. Really? Well if that’s true then eliminating these snakes from the pet trade will do nothing to stop this northerly migration. However, I’d like to point out that if these snakes were moving north at such a rate we would have seen them well north of the Everglades long ago… and yet we haven’t. So how is banning the 9 large constrictors an environmental issue? It’s not because it will have no impact, what so ever, on any environmental issue we may be facing in southern Florida.
    I’d also like to point out how much the USGS report resembles the so-called “studies” of Africanized Honey Bees back in the 1970’s. They were also media fueled paranoia. We were told that these bees posed a serious risk to the environment and personal well being given their aggressive nature. We were also told that they were heading north and making headway every year and that by the early 1980’s they’d be as far north as New York City… I live in Northern New Jersey, and I’m still waiting for the “Killer Bees” to arrive. Could it be that these “reports” were false and filled with little clinical study?
    If reports are going to be made about the issue of non-native species thriving in the Florida Everglades then let’s focus on facts and actual studies of the animals present in the Everglades, and how to address the issues. Instead of making sweeping theories based on paranoia and ignorance.
    – Mike Lynch

  9. snakelady
    November 9, 2009, 7:08 pm

    I would expect National Geographic to give a fair report of this issue. You’ve dropped the ball on this one.
    That bill would simply kill the reptile industry and put many people (even entire families) out of work.
    The United States Association of Reptile Keepers (USARK) has already been working with the state of Florida to remedy the situation in the Everglades. The proposed bill in your article will do NOTHING to remedy the problem. It will simply convert good law-abiding reptile owners and breeders into criminals overnight.
    Question: SINCE WHEN have boa constrictors been considered dangerous? Answer: NEVER!
    I have 2 boas, myself. I’ve never had a problem! There are rules for owning and handling large snakes. When those rules are followed, there are NO problems.
    USARK promotes proper treatment, handling, and caging of large reptiles.
    By the way, please check out the following youtube video before ever donating money to the HSUS. Instead, donate directly to your local humane society (They are NOT related).

  10. David Braun
    November 9, 2009, 7:03 pm

    Thanks for your comments. I will certainly read the material on the links you have provided and may well blog separately about further evidence before Congress.
    I did indeed blog about the report you mention, “Python Invasion of U.S. Unlikely, New Study Says”: http://blogs.nationalgeographic.com/blogs/news/chiefeditor/2008/08/giant-snake.html
    I am not at all biased against responsible ownership of exotic snakes, which would include making sure that they are not released into the wild. However, it is very well documented by many scientists that invasive species, from feral cats and dumped aquarium fish to all kinds of plants that have escaped from gardens, have done a lot of damage to America’s unique native species. And that’s something we all should be aware of, so as to encourage all of us to be less careless.
    Government agencies responsible for protecting native species reporting to Congress that invasives are causing big trouble is something that makes for legitimate debate.
    I appreciate you taking the trouble to make your comments and provide links to additional information. That way we can all be better informed about a complex situation.

  11. LevelHead
    November 9, 2009, 5:42 pm

    Please use caution and better research when reporting on such issues. Here is a PDF report that refutes much of the USGS report on Burmese Pythons ability to spread into other areas beside extreme South Florida.
    Burmese Python can in fact not expand further into the U.S. Many environmental needs must be met for any of these listed Constrictor species to populate the United States. In fact Boa Constrictors exist and have existed just a few miles South (few 100 mls south)in Mexico.These Boa Constrictors have existed in Mexico for thousands of years,yet have not established any populations in the United States. This proves there is no threat of the Pythons or other constrictors spreading across the United States and creating and establishing populations anywhere other than extreme South Florida.This paper I suggest you read , also addresses further issues on the Burmese Python and Everglades issue.
    Pdf entitled :
    On Burmese Pythons in the Everglades
    Questions Posed and Answered on the Issues of Pythons
    in South Florida and in Captivity
    David G. Barker and Tracy M. Barker

  12. dangles
    November 9, 2009, 5:27 pm

    Mr. Braun, I strongly urge you to read he research report written by researchers out of the City University of New York last year. It can be found here:
    That map you posted is from a USGS report that was extremely biased and incomplete, even wreckless in it’s over-exagerations. If the same parameters used to predict the potential expansion of the Burmese pythons ontheir states were used in their native habitat, the area ‘suitable’ for habitation by them would FAR exceed the actual known range, even expanding as far as Afganistan! That should tell you how faulty the USGS study actually is.
    Please read the document I linked to. This blog post you have authored has done nothing but pour gasoline on an already raging fire, needlessly descimating the reptile industry and causing more lost jobs in an already ailing economy.

  13. SpecialtySerpents
    November 9, 2009, 4:57 pm

    This article is obviously biased and one sided.
    Anyone who has watched or listened to the Congressional Hearing that took place on Friday November 6th will have noted Dr. Elliot Jacobson’s and Andrew Wyatt’s testimony from the United States Association of Reptile Keepers (USARK). Why is there no mention of either of them or their testimony in this article? Why is National Geographic not reporting on both sides of the issue? It is quite apparent that National Geographic has an extremely biased position on this issue. Here is a link with a COMPLETE list of witness testimony,

  14. aceace88
    November 9, 2009, 2:57 pm

    This article is totally one-sided. There is no mention of the House Judiciary Committee testimony of Dr. Elliott Jacobson, DVM or of Andrew Wyatt of the U.S. Association of Reptile Keepers (US ARK).
    Why is National Geographic being so biased? Do you have something to hide?