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U.S. proposes squeeze on large snakes

The U.S. Fish and Wildlife Service will propose to list the Burmese python and eight other large constrictor snakes that threaten the Everglades and other sensitive ecosystems as “injurious wildlife” under the Lacey Act, Secretary of the Interior Ken Salazar said this week.

Salazar made the announcement at the Port of New York, which serves as the largest point of entry in the U.S. for imports of wildlife and wildlife products. Last year, U.S. Fish and Wildlife Service Inspectors at John F. Kennedy International Airport handled more than 27,000 separate wildlife shipments valued at more than $1 billion, or 16 percent of all U.S. wildlife imports, FWS said in a news release.

The proposal, which will be open to public comment before Salazar makes a final decision, would prohibit importation and interstate transportation of the animals.

“The Burmese python and these other alien snakes are destroying some of our nation’s most treasured–and most fragile–ecosystems.”

“The Burmese python and these other alien snakes are destroying some of our nation’s most treasured–and most fragile–ecosystems,” Salazar said. “The Interior Department and states such as Florida are taking swift and common sense action to control and eliminate the populations of these snakes, but it is an uphill battle in ecosystems where they have no natural predators. If we are going to succeed, we must shut down the importation of the snakes and end the interstate commerce and transportation of them.”


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 was appended to written testimony handed to the U.S. Congress last year by the South Florida Water Management District. The agency urged prompt action at the federal level to limit the number of invasive pythons released into the wild. Read more about the agency’s presentation to Congress here

Illustration source: Skip Snow, Everglades National Park & Dr. Stephen Secor, University of Alabama

In total, wildlife inspectors stationed at ports across the nation processed more than 169,700 shipments of wildlife and wildlife products last year with an estimated value of $2.7 billion, FWS said in its statement of this week.

“Our wildlife inspectors are the front line of defense for the nation, combating illegal wildlife trafficking and preventing the importation of countless species of illegal injurious wildlife. This proposal will give them an additional tool to restrict imports that are causing significant ecological and economic damage, while giving our law enforcement agents the ability to restrict the spread of these species within our borders,” said U.S. Fish and Wildlife Service Director Sam Hamilton.

The nine species proposed for listing are: the Burmese python, northern African python, southern African python, reticulated python, green anaconda, yellow anaconda, Beni or Bolivian anaconda, DeSchauensee’s anaconda, and boa constrictor.

“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.

Popular pets 

Many of these large snakes are popular as pets, and are associated with a large domestic and international trade, FWS added. “Over the past 30 years, about a million individuals of these nine species have been imported into the United States, and current domestic production of some species likely exceeds import levels.”

Under the Lacey Act, the Secretary of the Interior is authorized to regulate the importation and interstate transport of species determined to be injurious to humans, the interests of agriculture, horticulture or forestry, and the welfare and survival of wildlife resources of the United States.

Senator Bill Nelson, D-FL and Representative Kendrick Meek, D-FL, have introduced legislation in Congress, supported by Secretary Salazar and the Obama Administration, which would also restrict importation and interstate sale and transportation of the nine species of constrictor snakes, FWS said. Salazr’s proposal “ensures that the injurious proposal will be considered through all available legislative and administrative avenues,” the agency said.

Public will be able to comment

The U.S. Fish and Wildlife Service will publish the proposed rule in the Federal Register in early February. At that time, the Service will also make a draft economic analysis and draft environmental analysis available to the public. The public will then have 60 days to comment on the proposal.

The Burmese python is currently distributed across many thousands of square miles in south Florida and a population of boa constrictors is established south of Miami. In addition, recent evidence strongly suggests a reproducing population of northern African pythons on the western boundaries of Miami, the FWS statement said.

“The U.S. Geological Survey issued a risk assessment last October that highlighted the threat. Of the nine large constrictors assessed, five were shown to pose a high risk to the health of the ecosystem, including the Burmese python, northern African python, southern African python, yellow anaconda, and boa constrictor. The remaining four large constrictors–the reticulated python, green anaconda, Beni or Bolivian anaconda, and DeSchauensee’s anaconda–were shown to pose a medium risk.”

Burmese-python-distribution-map.jpgThis map from USGS risk assessment for giant constrictors, published in 2009, suggests how much of the United States has a climate suitable (green area) for the establishment of the Burmese python.

Map courtesy of USGS

Reptile trade organizations such as the United States Association of Reptile Keepers (USARK) have been trying head-off the listing of the snakes under the Lacey Act, arguing that the USGS research was unscientific because it had not been properly reviewed by other scientists and experts. USGS has refuted this.

Burmese pythons and other large constrictor snakes are highly adaptable to new environments and are opportunistic in expanding their geographic range, FWS added. “More than 1,200 of the snakes have been removed from Everglades National Park since 2000, with others having been removed from the Florida Keys, along Florida’s west coast, and farther north along the Florida peninsula.

“Burmese pythons threaten many imperiled species and other wildlife. Two Burmese pythons were found near Crocodile Lake National Wildlife Refuge, and the remains of three endangered Key Largo wood rats were found in their stomachs.”


Burmese pythons are breeding in the wild. 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

Secretary Salazar strongly encouraged pet owners not to release snakes or any other pets into the wild.

“People may think that this is a convenient and humane way to be rid of unwanted animals, but as in the case of pythons and other constrictors, it can lead to devastating consequences for local wildlife populations and the ecosystems they depend on,” Salazar said.

Salazar said he has directed the Fish and Wildlife Service to conduct a comprehensive review of existing legal and regulatory authorities to address the invasive species issue on a broader scale.

“I’ve asked the U.S. Fish and Wildlife Service to make recommendations regarding the potential tools we need to address the invasive species challenge – both to combat existing invasive species problems and act more effectively to prevent the introduction of new invasive threats into our country,” Salazar said.

Read more about this controversial issue:

USGS defends python-climate study
The finding that much of the lower U.S. could host large exotic snakes was reviewed extensively by the world’s leading experts, says the U.S. Geological Survey.

Justification for Congressional python ban unscientific, researchers say
Biologists and veterinarians are urging the U.S. Congress to hold off on a ban on trade in pythons and other large exotic snakes until research into how much of a threat they pose to U.S. ecosystems has been thoroughly reviewed by independent scientists.

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.


Congress considers 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.


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 snakes 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 Everglades: Is 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. Ariana Smith
    March 22, 2015, 4:49 pm

    Helping the ecosystem? Wow some people did not pass science class. Research research RESEARCH. Pythons can be up to 32 ft long and can weight as much as a person. The wood rat is now an endangered species thanks to the Burmese python. Only predictors to these pythons are people, alligators, and tigers. Since we dont have tigers that leave us and alligators. We can only do so much and as of late, Alligators are loosing, Why? because of the size of these pythons. Read ALL the info you can and then make a statement. Boas usually do not get as large as the python which is why most concerns circle the Burmese pythons.

  2. Coltan
    Crystal river middle
    December 4, 2013, 1:56 pm

    That’s awesome

  3. eddie_indigo
    January 27, 2010, 1:19 pm

    More biased, non-science from the Dept. of Interior. Hand picking a few anecdotes of stomach contents proves nothing. Using that criteria, we could also conclude that the pythons are HELPING the ecosystem since pythons have been found that have had feral cats, which are undeniably harmful to indigenous wildlife, in their stomachs. Why are feral cats, feral boars and other pest animals not on the hypothetical python diet above? Also, why is there no discussion of what other animals eat pythons? Many wading birds EAT SNAKES and can decimate snake populations. A decent sized alligator will easily eat even a big python (Ironically, even the picture the USGS posted shows and alligator EATING a burmese python.)
    Also, why no discussion on what other animals (indigenous or introduced) besides Burmese pythons eat/kill endangered species like wood rats? That’s also relevant.
    As far as the USGS refuting the criticisms of its risk assessment, it was not successful. The risk assessment was flawed in many ways. Please see comments on the link: