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Herpetologist Shawn Heflick Answers Your Questions

Herpetologist Shawn Heflick

Herpetologist Shawn Heflick

Herpetologist Shawn Heflick, featured in Invasion of the Giant Pythons, is President of the Central Florida Herpetological Society. He has a permit to hunt down Burmese pythons in the Everglades, and he’ll be out in the field doing just that the weekend our program premieres.

Submit your questions for Shawn Heflick in the comments field below, and he’ll respond to them during the week of February 22.

Dr. Wyman asks:

What is your opinion of the USGS report and its prediction of the spread of these animals?

Shawn says:

Scientifically, I think the USGS report should have undergone a more stringent peer review process before being released. Issues with the use of data from the Indian python instead of the Burmese python, and speculative global climate change models would surely have raised red flags with colleagues in the peer review process. The recent cold snap in south Florida is also yielding interesting data, which includes many deaths within this wild Burmese population that would seem to refute the USGS report.

Teresa asks:

I’ve heard that it’s possible that there are tens of thousands of pythons in the Everglades. Do you think that this number is accurate? Is it an exaggeration, or are there really that many pythons in the Everglades?

Shawn says:

From being on the ground and in the field with these animals, myself and others believe that the true number is closer to between 5,000 to 10,000 animals. The 100,000 plus numbers are inflated and sensationalized by politicians and some of the local media, but no one has the real answer to exactly how many are out there.

Rebecca asks:

Is there any genetic evidence that the pythons in the Everglades are from diverse stock, as would be expected if the pythons are largely released/escaped pets? I’ve heard some say that many of the pythons are escaped from a military operation and that they are closely related genetically. Can you “shed” any light on this topic? Thanks.

Shawn says:

Hey Rebecca. There is very little genetic variation within this wild population. The genetic study done on this population suggests that the population stems from the Hurricane Andrew devastation in 1992. At least one facility had over 900 Burmese pythons at the time and was destroyed completely. This facility was within just a mile or so of what is believed to be the epicenter of the population, and it possessed animals from the same genetic origin. Since 1992 the FWC has put into place more stringent regulations on housing, disaster protocols and bio security in general.

Nancy asks:

Please tell me these snakes froze this winter!!!

Shawn says:

We are seeing a number of dead and dying pythons from the freeze. The data is still being collected, but it does appear that a large number have succumbed to the prolonged and severe cold. I think we will see a decreased breeding event for 2010 from this severe winter.

Douglas Bellizzi asks:

It’s not just the ecosystem. What about the danger to the human population? These animals are dangerous and they are stealthy. When it comes to the safety of human beings, there can be no apologia whatever for these animals.

Shawn says:

Hey Douglas. The human safety factor is NOT an issue with this wild population. Not one human has been attacked or injured from one of these wild pythons and they are not prone to attack humans unless molested or grabbed. You are much more likely to be bitten by your own pet dog, get into a car accident or struck by lightning.

Suzanne asks:

Would these snakes ever attack a person in the open? Do these snakes enter residential areas in search of food or warmth? And is there something they don’t like or stay away from that someone could carry, in case of a run-in with a python?

Shawn says:

Hey Suzanne. These wild pythons have not attacked humans and are NOT a public safety issue. They may venture into rural or suburban areas, but are quickly spotted, run over on roads or captured. The best thing to carry is common sense… stay away from one if you see it and call FWC or your local police department.

Nathan B asks:

What, in your opinion, is the most effective solution to address this South Florida issue? There have been a number of solutions posed that failed to take into account the limited scale of the issue and attempted instead to make it a national issue. HR669, S373, and the Injurious Species Provisions of the Lacey Act penalize responsible owners and breeders of constrictor snakes across the other 49 states where the potential for survivability of these snakes in the wild is absolutely nil. Eliminating these animals from the pet trade does not address the established population in the far south of Florida and only harms the responsible keepers and small businesses that make up the captive-bred reptile industry.

Shawn says:

Good questions, Nathan. FWC has already implemented serious regulations over the last several years which have worked! The numbers of large pythons in the pet trade is now almost non-existent and the vast majority of people who still own them are permitted, responsible, educated people who are helping FWC with the problems through their 24/7 Amnesty Program. A BAN is NOT the answer. Historically bans do not work. They simply force things underground. Many of my biologist peers with whom I have spoken agree that a ban will cause massive problems for the state of Florida and the U.S. It will create a black market, force real releases of “now worthless or illegal” animals and create an atmosphere of distrust with the government. Regulations are the way to proceed, because they still give wildlife agencies the ability to keep tabs and regulate the animals.

Tony F. asks:

Why must the pythons be destroyed? Why not capture and relocate them to their natural habitat like some other wildlife programs out there? It’s understandable people may not want them there, especially if they are not native to the land, but must they really be destroyed? I personally love pythons. I prefer ball pythons since they stay relatively small though. I had a Burmese before but it died due to illness. I would just hope people could find a better solution rather than eradication. Education would be a start. If the cause of them being there is due to people “dumping them off” when they are no longer wanted or get too big, the problem will never be fixed until people learn not to dump them there in the first place. Owning a Burmese or any other large snake is just like owning any other pet. Do your research and use some common sense before purchasing one.

Shawn says:

I truly enjoy these animals as well, Tony, but you cannot relocate animals back into Southeast Asia due to disease concerns and the massive monetary costs involved. And you are right about people educating themselves before they make a purchase… no matter whether it is a dog, cat, fish, bird or reptile!

Matt asks:

Don’t all tropical wetlands except the Everglades have large constrictors and crocodilians present? What extended effect would large constrictors have on the Everglades in the long run, considering the skin trade and tourist dollars? What effect did the hard freeze have on the Asian and South American feral animals in South Florida, considering the damaging effect it had on native reptiles? Are there any plans in place for dealing with iguanas, Cuban anoles, or kudzu? Does anyone actually think that pythons could survive more that a year anywhere else in North America? Do normal people ever do the math on how many kids die from drowning or infanticide compared to the numbers that die from constrictors worldwide? Aren’t mustangs an invasive species? What’s your professional opinion on the considered “Python Ban” when they haven’t fully enforced the recently enacted R.O.C. laws in Florida? What in the world does the U.S.G.S. know about reptiles, outside of Disney cartoons? Is everyone’s normal reaction to new events to ignore it for a while, then dramatically over react?

Shawn says:

All good questions, Matt. Yes, many of the tropical wetlands have native species of crocodilians and boids, but the Everglades did not… until now. We do not know what long term effects the pythons might have on the Everglades, but they do have the potential to do damage to the indigenous wildlife and thus a proactive approach is best. The recent freeze has caused problems with many exotics (and native species) and numbers of iguanas, pythons, fish, frogs and plants were knocked back by the cold temperatures, but not eradicated. A ban is NOT the answer, but instead the new FWC regulations need to be given more time to work. They already have stopped most of the pet trade in large constrictors in the state.

Victor W. asks:

I am a member of the Kansas Herpetology Society. I am a teacher here in Kansas so I am off in the summer. If you were to have a need for summer python help, my wife may let me come down for a month. All I need is a cheap place to crash.

Shawn says:

Hey Victor. Kudos on being a member of the KHS. Herpetological Societies are a huge educational resource and a great way to get educated about reptiles and amphibians! I’m sure we could find some fellow herpers to aid you in your aspirations for herping Florida.

Jon asks:

Unanswered questions that come to mind: 1. How long do the pythons live? 2. How big do they grow? I heard 15′, 20′, 25′ during the course of the show. Do females grow bigger than males? 3. How far north are they likely to spread? Do they hibernate? 4. Why do some Burmese pythons have pale markings, and others a deep pattern? 5. Are they the top predator in their original Burmese habitat? What do they co-exist with there? How do people deal with them? 6. Could the meat and skin become a new Florida export? 7. What other extermination methods are under consideration besides hunting individual snakes? 8. The program mentioned reticulated pythons, but focused on Burmese. What is the difference? Are the reticulated also invading South Florida?

Shawn says:

They can live over 25 years in captivity… in the wild it is unknown. Males may reach 14 feet while females can get over 20 feet. It is unlikely that they will move any further north than they already have due to cold temperature restrictions. They do not hibernate, as they evolved in a tropical system in Southeast Asia. Like most species, there is variability in their color and patterns. Many dark animals you see may also be in late stages of ecdysis (shedding their skin). They are a top predator in their native systems, but have predators as well. Southeast Asia has crocodiles, large cats, birds of prey and many more. Remember that most of the hatchlings are eaten before ever making it to adulthood, so many animals prey upon them. Contrary to popular belief, they are not a threat to people in their native range or in the U.S. The skin could potentially be of value, but there are reports that the meat has high levels of mercury in it. Pheromone baiting, long net trapping, infrared aerial tracking are a few other management strategies that have been considered. The reticulated python is a different species of large constrictor from Asia as well, but it is not invading South Florida.

El Sanburg asks:

What are the actual population – and range – estimates based upon for the feral pythons and lizards: hype, fear, politics, or true science? We really need to know the results of factual scientific data and not, as several animal-control people presented, ‘guesstimates’ or beliefs based on unsystematic and biased collection samples. I would very much appreciate a lead on the published references for these data. With respect to the Florida pythons’ stomach contents that were reported in this program: what are the complete species lists and individual counts in the stomach contents for each and all of the snakes; how many snakes were sacrificed for the study population; what size, age estimates, and sex were these snakes; how many were gravid; where were their capture locations; in what year, season and weather was each snake captured; how many snakes were thriving, versus starving or ill; and why are we ONLY presented, in this program, with the endangered species that were eaten and not the full range of presumably more-available non-endangered animals?

Shawn says:

All good questions El. Much of what you ask has not been tabulated between the different agencies that are involved in this program… Department of Interior, South Florida Water Management and the FWC. Much of this data is also being written into scientific papers right now and thus are not currently in published references as yet. As far as the actual population numbers… there is no way to know that. True numbers for any species on this planet are not known unless they are so endangered that there are only a handful left. Population numbers are built on field counts and extrapolated or plugged into models. Clearly we cannot count every snake. Distribution is a little easier, but still not 100% accurate. This population appears to be centered in South Florida outside of Florida City and Homestead and into the Everglades National Park. Yes, the majority of the prey items of the pythons are NOT endangered and include rodents, lagomorphs, birds, a deer, a bobcat and a handful of small alligators.

Reji asks:

How do I discuss this topic with folks I care about that are working in that area?

Shawn says:

Ask lots of questions! Gather as much info as possible so you are informed. Remember that even the “experts” don’t have all the answers. We are still trying to figure it out!

Isaac Pitts asks:

a.) What would I need to get a permit to hunt pythons in Florida? b.) Who hires the hunters, and do they plan on hiring more people to hunt pythons in Florida? c.) What does this job pay \ is it a hobby? d.) Are you allowed to hunt in the Everglades National Park, or do you have to find them outside of the park? e.) Is there a current market for the skin\meat of the python’s that are hunted? f.) Do you work with people that euthanize or is that a separate group of people hired by the Florida government \ park service?

Shawn says:

Go to www.myfwc.com for permit requirements and more info about the program. The hunters are not hired… we are all volunteers, and there is no pay. The permits for the state (FWC) and the Everglades National Park are two different permits/programs. There is not currently a market for python skin, but it is being looked at. The meat has high levels of mercury in it and thus is not good for human consumption. Some animals are euthanized, some are taken for further studies and research.

Melissa Kendall asks:

A recent article stated that Fish and Game estimates that 50% of non native green iguanas were killed in the latest cold snap in the Glades. How many large snakes do you think were killed? What temperatures are usually necessary to dispatch a large snake like a Burmese?

Shawn says:

Hey Melissa. I think the 50% may be a low figure for iguana mortality. There is no real way to know how many Burmese pythons died from the cold, but we are finding approximately the same amount dead as alive. Prolonged temperatures in the 30s and 40s (Fahrenheit) can be deadly for these tropical animals. Freezes are killers for this species.

Julie asks:

As a former employee of Flamingo, I saw pythons kept as pets. I lived there in the late 80s. Is it possible that the release of these animals when the season ended has caused this invasion?

Shawn says:

No doubt, Julie, that some have been dropped by uninformed or irresponsible pet owners, but in my opinion not enough to have found one another and established a population. Look up the term Propagule Pressure for a better understanding of what I am referring to. Everything (genetic study, absence of color mutations, epicenter, etc.) points to Hurricane Andrew as the major source for this wild population.

Aaron Y asks:

1. What empirical data exists about the impact of pythons on the Everglades beyond people simply seeing them? 2. How does python destruction of native flora and fauna compare with destruction caused by housing development, agricultural development, human pollution, taking swamp buggy rides and other human activities or human proliferated animals? 3. Regarding the fear of danger to humans, what are the comparisons of snake related fatalities to dog/livestock/horses or other animals that humans interact with? For that matter what are the fatality comparisons between snakes and alcohol related fatalities or heart disease or cancer? 4. What studies have been done on what the pythons eat at each stage of their lives to help show the impact they are actually having? My concern is the disproportionate fear [about] this snakes seems [to] exaggerate the issue to the point that legislation is proposed which would essentially ban the keeping and sales of almost ALL foreign plants and animals without any actual scientific backing. While non-native species proliferation and habitat destruction are big issues, using them as sensationalist marketing tactics for increasing viewership is irresponsible. I look forward to the show to see how this issue is portrayed.

Shawn says:

We have empirical data that tells us that the population is breeding, we know that they are feeding on a wildlife within the population and we know they that there are more than just a handful of them out there. Regarding how the impact of pythons compares to the impact of human development, it pales in comparison…humans are and always will be the largest injurious species on this planet. NO HUMAN has ever been attacked or injured by one of these wild pythons. There is ongoing data collection of gut content from all pythons captured in the wild to help answer these questions about what they eat. I think PBS did a good job at trying to show the issue from both sides… but the documentary was only 1 hour in length and this is a topic that would take days to fully explore.

Marc asks:

I kept hearing over and over that there are 10,000 Burmese pythons in ENP. Question #1 What method was used in quantifying the Burmese python population in ENP? Question #2 How did you determine that predators were unsuccessful in preying upon neonate and juvenile pythons? You showed some footage showing a king snake letting go of a python and made a statement that they are unable to prey upon them. was this based upon that single observation?? I ask the same question about the raccoon, alligator and bird of prey.. you stated that this was because the python had a strike as a defense mechanism, but this same mechanism is used by all of the local snake species as well. In fact king snakes commonly prey upon venomous snakes that are much larger than neonate Burmese pythons. The program makes it sound like Burmese pythons have absolutely no chance of predation, when in fact it has been documented that several species are using them as a food source. Question #3 The footage showing the female Burmese python with 3 males within 50 feet during a live shoot. This seemed almost to lucky to be true. I find it very odd that 2 of those males.. when being approached by cameramen, were laying on top of tall grasses almost as if they had been gently placed there…. Burmese pythons don’t move that way… they slide through the grass… not on top of it…. Also the lighting in 2 of the shots looked to be taken at different times of the day, but edited to look like a possible breeding group was found. What really happened out there? Why was there no mention of the climate acting as a barrier for these snakes?? There was also no mention of the transmitter study that yielded numerous dead pythons following the winter. Question #4 Why were they allowing pythons to stay in ENP for tourists to see? It really seems more like Florida is using the Burmese Python to get tourists, and pull in extra dollars to fund ENP restoration program, when in fact there are many other invasive species that have much greater fecundity and cause much more ecological damage? I am rather disappointed that a fellow scientist would participate in this kind of pseudoscience, and conduct research that produces opinionated conclusions that are motivated by political agenda.

Shawn says:

Like any population…there is a certain degree of error due to the fact that you cannot count every animal in the wild. Numbers have been informed estimates based on filed biologists, permittees and models. Regarding the scene you mention, I honestly cannot tell you as I was not present for the National Park shoot, but breeding aggregations have been known to occur. This was filmed long before the cold snap occurred. I am unclear to your reference to “allowing pythons to stay in the ENP” for tourists as this is not the case. The reference in the documentary was that tourists may be interested in seeing them. You are correct that many invasives are far more injurious than the pythons, but unfortunately they do hold sway over many from the unwarranted fear they generate in some humans. Not sure if you are referring to me or not [when you say you’re “disappointed that a fellow scientist would participate in this kind of pseudoscience”], but my role in this was overall relatively small and I stand by what is attributed to me. Remember that science is about discovery and the ability to openly debate, support or refute the data. That is what makes it science. Also remember that research and television are different arenas and much of the scientific details are left out due to a documentary being 1 hour and the amount of material available to cover.

Gary Walters says:

Isn’t it time to start eradicating these creatures instead of studying them? Maybe you should have a state funded open season on the Burmese python paying some fair amount for each kill brought in and verified. Also why not try using some traps baited with female Python pheromones to capture as many male Pythons as possible and destroy them?

Shawn says:

I/We are doing both [eradicating and studying the pythons]. Each animal that is captured is removed from the ecosystem and data is collected for the study, which will allow us to have a better handle on the population and how to deal with it. Bounties are known to cause additional problems, but FWC is opening up the program to additional stakeholders to broaden the program. Pheromone baiting is being considered!

Jenn asks:

I am wondering what all the negativity is about. I understand that many who are here are interested from a fellow scientists point of view, but what is the matter with the pseudoscience in this particular situation? I found this show to be completely amazing. I don’t care that it was shot at different times throughout the day nor do I care about the funding or actual population of pythons in the ENP. I’m sorry that I am crashing this “comment party” with no actual questions, but I would like to say, from the perspective of a viewer with no bias to the area of science, that I thoroughly enjoyed this program. If there were more unnecessary facts and less of the “sensationalism”, I know there would have been two less viewers tuning in on Sunday night. Good Show. Thanks for the “mellow-drama”. I plan to look for future listings of this program.

Shawn says:

I am glad you enjoyed it Jenn. Ultimately, for most people, most shows need to be about a balance of science and entertainment.

Kimberly asks:

Hi Shawn! First, I would like to thank you for all the hard work you do in educating people about the facts and not blowing this problem out of proportion like much of the media. What are your thoughts on the proposed python ban (S373)? It is my understanding that this proposed ban will not have any effect of the Everglades situation which it was originally written for. Also, it seems many people blame pet owners and commercial facilities for the release of pet pythons into the Everglades. There has been little mention of mass escapes from Hurricane Andrew in 1992, which largely contributes to the population. Do you think it would be feasible to micro chip large constrictors (much like they do with dogs)? I could be mistaken, but if pet owners are really releasing pythons, micro-chipping would certainly prove that and hefty fines would help with the funding needed to rid the Everglades of Burmese pythons.

Shawn says:

Hey Kimberly. In my opinion, the data does point to escapes from the destruction of Hurricane Andrew for this wild population. Micro-chipping is being currently used and is a legitimate tool for identification. As for S373 and all the other bans…they are sadly based on politics instead of facts and logic. They will nothing to help the problem, BUT THEY WILL EXACERBATE IT.

Donna Rae asks:

Hi, Shawn – We didn’t see the beginning of the show (yet), but it was very interesting. We are wondering if python meat is EDIBLE. If so, we are thinking it would be a great thing for Floridians to serve them up! In Kenya, the carnivore restaurant does very well with local, native harvesting… perhaps python (barbequed or …?) could be a tourist attraction and tasty for locals too? Feed the people, make some money and get rid of some of the invading species. Could be a win-win for most all – including the poor birds and wood rats! Perhaps the Chamber of Commerce could have a cooking contest/festival and also promote education about not releasing pets/non-native species…and the interesting python… perhaps along with the amnesty day featured on the show (or that same week)? Thank you for your response! Very interesting!

Shawn says:

Hey Donna. Unfortunately, the pythons are said to have high levels of mercury in them and thus are NOT good for human consumption.

Josh asks:

Is there any particular reason why only Burmese pythons have invaded the Everglades and not other large constrictors as well?

Shawn says:

There has never been a large insertion of other large constrictors into the Everglades like there was with Burmese pythons from the destruction of Hurricane Andrew in 1992. For most invasives it takes a large number of specimens or large number of insertion events to establish a breeding population.

Beth H asks:

You said, “The reticulated python is a different species of large constrictor from Asia as well, but it is not invading South Florida.” Why is that species not invading? Is it not a snake that people like to collect, and then release when it gets too big to handle? Is there a habitat difference? Is this related to the big escape of a collection of Burmese pythons, because of a hurricane?

Shawn says:

You are correct… a large number of Retics never escaped due to the destruction of Hurricane Andrew or any other hurricane. And now that FWC is doing an even better job at regulating the large constrictors and other Reptiles of Concern it should never happen period.

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TRANSCRIPT

FLORIDA -- A HOTSPOT FOR TOURISTS... AND EXOTIC PETS.

A BURMESE PYTHON.

THESE FOREIGN SNAKES ARE NOW LIVING WILD HERE.

THE MASSIVE SERPENTS ARE INVADING SOUTHERN FLORIDA.

THEY CAN GROW 26 FEET LONG AND BE AS THICK AS A TELEPHONE POLE.

THESE PREDATORS ARE POWERFUL ENOUGH TO KILL PEOPLE.

WE'RE GOING TO FOLLOW HUNTERS AS THEY TRACK THEM DOWN.

FIND OUT WHAT THEY EAT.

MEET SCIENTISTS INVESTIGATING THE SNAKES INSIDE AND OUT.

CATCH GIANTS DEEP IN THE WILDERNESS.

DISCOVER OTHER EXOTIC INVADERS.. AND ANALYZE A STRIKE.

AS RECENTLY AS THE 1990s, THERE WERE HARDLY ANY WILD PYTHONS IN FLORIDA.

NOW THERE ARE THOUSANDS, PERHAPS TENS OF THOUSANDS.

SO HOW DID THIS INVASION START?

IT REALLY IS A CASE OF SNAKES ON A PLANE.

12,000 SHIPMENTS OF WILDLIFE ARRIVE EVERY YEAR THROUGH MIAMI.

INCLUDING, IN THE LAST FOUR YEARS ALONE, OVER A 140,000 WILD-CAUGHT PYTHONS.

THERE ARE OTHER EXOTIC ANIMALS, TOO -- THESE ARE GREEN IGUANAS.

BABY BURMESE ARE JUST 20 INCHES LONG, BUT KEPT WARM AND WELL-FED, THEY GROW AND GROW.

IN JUST A YEAR, A PYTHON CAN DOUBLE IN SIZE AND SWALLOW FROZEN RATS WHOLE.

SOON, LARGE RABBITS ARE ON THE MENU.

THE LARGEST CAPTIVE PYTHONS -- THIS IS A RETICULATED PYTHON -- REALLY GO WHOLE HOG.

THEY CAN GOBBLE UP A PIG WITH EASE.

MANY OWNERS ARE ASTOUNDED TO FIND THAT AT JUST 2 YEARS OLD, THEIR PET PYTHON MAY BE 11 TO 12 FEET LONG AND WEIGH ALMOST 200 POUNDS.

SUDDENLY, THEY HAVE TOO MUCH SNAKE ON THEIR HANDS.

THE RESULT IS THAT MANY UNWANTED PETS HAVE BEEN IRRESPONSIBLY RELEASED INTO THE WILD.

BUT THE MAIN PYTHON INVASION FORCE WAS UNLEASHED BY STORMS.

OVER THE YEARS, SOME OF FLORIDA'S ANIMAL WAREHOUSES HAVE BEEN HIT BY HURRICANES.

SNAKES ESCAPED AND SLITHERED FREE.

THE INVADERS OCCUPIED GROUND NEAR MIAMI.

WITH PLENTY OF FOOD AND HIDING PLACES, THE HABITAT IS SIMILAR TO THEIR ORIGINAL ASIAN HOME.

IT WASN'T LONG BEFORE THE SNAKES PUSHED DEEPER INTO THE INTERIOR OF THE STATE.

SOUTHERN FLORIDA'S THOUSANDS OF MILES OF WATERWAYS PROVIDE A FREEWAY FOR PYTHONS TO TRAVEL.

SNAKES SWIM GRACEFULLY IN ELEGANT CURVES, PUSHING AGAINST THE RESISTANCE OF THE WATER TO MOVE FORWARD.

THE PYTHONS HAVE ENDURANCE, TOO -- THEY CAN SWIM AT LEAST SIX MILES WITHOUT STOPPING.

PYTHONS USUALLY SWIM AT THE SURFACE, BUT IF THEY SENSE DANGER, THEY CAN HOLD THEIR BREATH FOR UP TO HALF AN HOUR.

OCCASIONALLY, THEY AMBUSH PREY FROM THE WATER, BUT DRIER AREAS ARE GOOD HUNTING GROUNDS, TOO.

THIS IS A NOW-DEFUNCT ROCKET TESTING SITE JUST 20 MILES FROM MIAMI.

IT'S PRIME PYTHON HABITAT.

HERPETOLOGIST SHAWN HEFLICK HAS A PERMIT TO HUNT DOWN PYTHONS.

HE'S HOLDING THE RED BALLOONS BECAUSE THEY MAKE PERFECT TARGETS FOR A STRIKING SNAKE.

Heflick: BURMESE PYTHONS -- DOCILE IN CAPTIVITY BUT A WHOLE DIFFERENT BALLGAME IN THE WILD.

HO HO!

Abraham: NOW, THE ACTION IS SLOWED DOWN OVER 200 TIMES.

AT THIS SPEED, A STRIKE IS AWE-INSPIRING.

PYTHONS HAVE HEAT-SENSING PITS ON THEIR FACES... SO THEY EASILY LOCK ONTO A BALLOON FILLED WITH WARM WATER.

Heflick: GOT TO PICK UP MY TRASH, OH! THEN, I'VE GOT TO GET THIS GUY.

THIS IS A LITTLE MALE. MALES HAVE LARGER SPURS, AND THEY UTILIZE THESE TO TICKLE THE FEMALE DURING BREEDING.

WHAT I'VE GOT TO DO IS GET THIS GUY BAGGED, HE DOESN'T BELONG HERE.

LET'S GO SEE IF WE CAN FIND SOME MORE.

Abraham: SHAWN'S CHANCES ARE GOOD.

PYTHONS CAN BE THICK ON THE GROUND HERE.

Heflick: WONDERFUL ANIMAL.

LOOKS LIKE A MALE.

WHOA! THAT'S WHAT THEY DO, THEY ARE A FAST-STRIKING PREDATOR.

GOT TO GET HIM RIGHT BEHIND THE HEAD.

OH! LOOK AT THAT MOUTH, FULL OF TEETH, BUT YOU CAN'T SEE 'EM BECAUSE THEY'RE COVERED BY GUMS -- NOT LIKE A VENOMOUS SNAKE.

BUT I'VE GOT A SKULL IN MY POCKET OF A BURMESE PYTHON.

AND YOU CAN SEE FOUR ROWS ON THE TOP.

THEN THERE ARE ANOTHER TWO ROWS ON THE BOTTOM, THE RECURVED TEETH, ABOUT A HUNDRED OR SO.

THEY USE IT TO SECURE THEIR PREY, LATCH ON, THEY THROW A COIL AROUND IT, AND THEN THEY SUFFOCATE IT.

AND ALSO, IF YOU LOOK CLOSELY, YOU CAN SEE TWO PITS THAT ARE HEAT-SENSING, AND THAT'S HOW THEY FIND THEIR WARM-BLOODED PREY AND THAT'S HOW THE OTHER ONE DETECTED THE WARMTH OF THE WATER IN THAT BALLOON.

THIS GUY IS TRULY A MAGNIFICENT ANIMAL.

ALL RIGHT, IN YOU GO, INTO A NEW HOME.

GREAT ANIMAL.

Abraham: SHAWN'S PAIR OF SNAKES WILL HARDLY DENT THE PYTHON ARMY.

NEARBY, IN THE SHALLOW WATERS OF EVERGLADES NATIONAL PARK, TENS OF THOUSANDS OF BURMESE PYTHONS THRIVE.

THE WATER SLIDES SLOWLY THROUGH GREAT SWATHS OF SAW GRASS.

WHERE THERE'S HIGHER GROUND, FORESTS OF SLASH PINES AND OTHER TREES GROW.

WATER FLOWS TOWARD THE SEA AT A QUARTER OF A MILE A DAY.

CYPRESS TREES THRIVE IN THE SHALLOWS AND CAN TOWER 120 FEET INTO THE SKY.

AT FLORIDA BAY, THE RIVER SPILLS INTO THE OCEAN AND MANGROVES FLOURISH.

THIS WILDERNESS IS FAMOUS WORLD-WIDE FOR ITS WATERBIRDS... AND OTHER FABULOUS WILDLIFE.

IN THEIR ASIAN HOMELAND, PYTHONS EAT WATERBIRDS.

COULD THIS CORMORANT IN THE EVERGLADES BECOME PREY TO A PYTHON?

PERHAPS ANHINGAS ARE ON THE MENU TOO.

THEY'RE A COMMON SIGHT HERE.

UNLIKE DUCKS, THEY DON'T HAVE WATERPROOF FEATHERS.

WET PLUMAGE MAKES IT EASIER FOR THEM TO GET UNDERWATER FAST.

THEY'RE ALSO CALLED SNAKE BIRDS, AND YOU CAN SEE WHY WHEN THEY SURFACE.

THEY DON'T SEIZE THEIR PREY WITH THEIR BEAKS, THESE BIRDS ARE SPEAR FISHERS.

THE UNFORTUNATE FISH HAS BEEN IMPALED ON A RAZOR-SHARP BILL.

IT TAKES A BIT OF FANCY BEAK-WORK TO FREE THE FISH.

THERE ARE RESIDENT REPTILES HERE, TOO.

COULD PYTHONS HAVE AN IMPACT ON THEM?

THE LARGEST NATIVE SNAKE IN THE U.S. IS THIS ONE.

THE EASTERN INDIGO SNAKE.

THEY'RE AN ENDANGERED SPECIES.

THEIR FAVORITE HABITAT IS LONG LEAF PINE.

95% OF THAT HAS BEEN CLEARED BY PEOPLE.

AT FIRST GLANCE, THEY LOOK JET-BLACK, BUT IN THE SUN THEY SPARKLE LIKE JEWELS.

MICROSCOPIC RIDGES ON THE SNAKE'S SKIN REFLECT AND SPLIT LIGHT INTO DIFFERENT WAVELENGTHS.

IT'S A NON-VENOMOUS SPECIES.

THE BIGGEST ONE EVER CAUGHT WAS 8 1/2 FEET.

THE INDIGO MAY HAVE ONCE BEEN THE BIGGEST SNAKE IN AMERICA, BUT IT'S DWARFED BY THE BURMESE PYTHON.

A LARGE INDIGO SNAKE MIGHT TIP THE SCALES AT 13 POUNDS.

AN ADULT BURMESE CAN BE 15 TIMES HEAVIER.

THE INVADER CERTAINLY PUTS THE INDIGO IN THE SHADE.

PYTHONS COULD POSE A THREAT TO NATIVE SNAKES BY COMPETING FOR FOOD AND OCCUPYING THE BEST LAIRS.

THE EVERGLADES ARE FAMOUS FOR REPTILIAN PREDATORS OF THEIR OWN... ALLIGATORS.

CAN THE PYTHON MUSCLE IN ON EVEN THESE GIANTS?

TO ATTRACT MATES AND DETER RIVALS, MALES GENERATE SUCH LOW, LOUD ROARS, THE WATER AROUND THEM DANCES.

ALLIGATORS WERE ONCE THE UNDISPUTED REPTILE KINGS OF THE EVERGLADES.

BUT WHEN PUSH COMES TO SHOVE, WHO WOULD WIN A BATTLE NOW?

ALLIGATOR... OR PYTHON?

IT ALL DEPENDS ON WHICH ONE IS BIGGER.

A LARGE GATOR CAN BITE DOWN WITH OVER 2,000 POUNDS OF FORCE.

A WELL-AIMED BITE ON A PYTHON'S HEAD KILLS IT ALMOST INSTANTLY.

BUT THE ALLIGATOR HAS BITTEN OFF MORE THAN IT CAN CHEW.

THE SNAKE IS TOO LARGE TO SWALLOW.

STASHING THE SERPENT UNDERWATER WILL ALLOW THE GATOR TO RETURN TO BITE OFF CHUNKS, ONCE THE FLESH HAS ROTTED.

BIG GATORS CERTAINLY KILL PYTHONS BUT THE TABLES CAN BE TURNED.

PYTHONS BEGIN WITH A LIGHTNING-FAST STRIKE.

THIS ONE GRABBED A GATOR WITH ITS RAZOR-SHARP TEETH.

LACKING VENOM, IT HAD TO USE MUSCLE-POWER TO KILL ITS VICTIM.

NEW RESEARCH HAS SHOWN THAT AS A SNAKE'S COILS TIGHTEN, THEY CAUSE A SHARP RISE IN THE PREY'S BLOOD PRESSURE.

SO, THE ALLIGATOR IS AS LIKELY TO HAVE DIED FROM BURST BLOOD VESSELS AS FROM SUFFOCATION.

SNAKE SKIN IS SO FLEXIBLE, IT CAN BE STRETCHED AROUND THE LARGEST OF MEALS WITHOUT TEARING, EVEN A TOUGH, ARMORED ALLIGATOR.

IN A MATTER OF DAYS, POWERFUL STOMACH ACID WILL COMPLETELY DISSOLVE THE MEAL.

THIS IS AN INCREDIBLE FEAT -- THE PYTHON HAS SWALLOWED AN ALLIGATOR HALF AS LARGE AS ITSELF.

BUT SOMETHING JUST AS REMARKABLE IS ABOUT TO HAPPEN INSIDE THE SNAKE.

HOW DOES IT COPE WITH THIS MASSIVE MEAL?

TO LEARN HOW THAT HAPPENS AND MORE ABOUT SNAKE PHYSIOLOGY, SCIENTISTS EMPLOY SOME HIGH-TECH PROCEDURES.

IN CAPTIVITY, RATS, NOT ALLIGATORS, ARE ON THE MENU.

Man: ALL RIGHT, HE'S GOT IT NOW.

Abraham: STEPHEN SECOR IS A PROFESSOR AND TEAM LEADER AT THE UNIVERSITY OF ALABAMA.

HE WANTS TO UNDERSTAND HOW SNAKES CAN STOMACH THEIR PREY.

Secor: WHAT AN AMAZING ANIMAL THE PYTHON IS.

CONSIDER -- HERE'S AN ANIMAL THAT CAN GO A MONTH, EVEN A YEAR WITHOUT EATING, AND THEN ABLE TO CAPTURE, INGEST AND DIGEST A MEAL THAT'S EQUAL TO HALF ITS OWN BODY SIZE.

Abraham: AN X-RAY WILL PROBE THE SNAKE'S SECRETS.

Secor: ALL RIGHT, LET'S GET HIM STRETCHED OUT.

OKAY, GET HIM IN THE CENTER.

RELAXED.

OKAY, YOU READY?

Secor: GOOD, YEP.

YESTERDAY, THIS SNAKE ATE A MASSIVE MEAL.

THE RAT IT CONSUMED WEIGHED MORE THAN A THIRD OF THE SNAKE'S OWN BODY MASS.

WE'RE NOW X-RAYING THE SNAKE SO THAT WE CAN TRACK THE BREAKDOWN OF THE PREY, THE RAT, WITHIN THE SNAKE'S STOMACH.

Man: RELAX A LITTLE BIT.

Secor: ARE YOU READY?

Man: ALL RIGHT, OOPS WAIT -- OKAY, GO... Secor: OKAY? Man: YEP -- GOT IT.

Secor: GREAT.

WHAT WE SEE HERE IS THE RAT INSIDE THE PYTHON'S STOMACH THAT WE JUST X-RAYED.

WE HAVE THE FULL RAT SKULL -- THE UPPER JAW, LOWER JAW, AND ALL THE BONES ARE STILL INTACT.

SO THIS IS THE SNAKE'S STOMACH, IT ONLY ENCOMPASSES THIS PART OF THE RAT.

SO THIS PART GETS BROKEN DOWN FIRST, AND THE REST OF THE RAT, WHICH RIGHT NOW IS IN THE ESOPHAGUS, WILL THEN MOVE FORWARD AND MOVE INTO THE STOMACH AND THEN BE BROKEN DOWN BY THE HYDROCHLORIC ACID AND THE ENZYME PEPSIN.

WITHIN SIX DAYS, WHAT'S GOING TO BE AMAZING IS THIS RAT WILL BE COMPLETELY GONE.

THIS IS AN X-RAY OF AN ALLIGATOR CONSUMED BY A PYTHON.

NOW WE KNOW IN THE EVERGLADES THAT PYTHONS ARE EATING ALLIGATORS AND THEY CAN DO SO QUITE EFFICIENTLY.

WITHIN ONE DAY, WE START SEEING A LITTLE BIT OF BREAKDOWN OCCURRING IN THE SNOUT OF THE ALLIGATOR.

BY TWO DAYS, HALF THE SKULL IS MISSING, PARTS OF THE FORELIMB HAVE ALREADY BEEN BROKEN DOWN.

AT THREE DAYS, ONLY A SMALL PART OF THE SKULL IS REMAINING.

AT FOUR DAYS AFTER FEEDING, PRETTY MUCH ALL WE HAVE IS PARTS OF THE HIND-LIMBS AND A LITTLE BIT OF THE ALLIGATOR'S TAIL.

BY FIVE DAYS JUST A SCATTERING OF SMALL BONES.

AND AT SIX DAYS IT'S ALL GONE, EVERYTHING HAS BEEN BROKEN DOWN AND PASSED INTO THE SMALL INTESTINE.

THESE SNAKES HAVE A TREMENDOUS CAPACITY TO BREAK DOWN ANY PREY ITEM WITHIN THEIR STOMACH.

THEY ARE EXTREMELY EFFICIENT HUNTERS AND DIGESTERS.

IN OUR STUDIES ON THE DIGESTIVE EFFICIENCY OF PYTHONS, WE'VE ESTIMATED THAT AN ADULT PYTHON, ABOUT 12 FEET LONG IN THE EVERGLADES, WOULD HAVE CONSUMED 70 DEER MICE, 30 COTTON RATS, 15 SQUIRRELS, A DOZEN RABBITS AND SEVERAL RACCOONS.

Abraham: IT TAKES A LOT OF FOOD TO GROW A 12-FOOT PYTHON.

NATIVE ANIMALS COULD BE UNDER THREAT, INCLUDING THE 36 SPECIES THAT ARE FEDERALLY PROTECTED IN THE NATIONAL PARK.

WOOD STORKS ARE ONE OF THEM.

THEY HAVE A WINGSPAN OF UP TO 6 FEET, MORE THAN THE HEIGHT OF AN AVERAGE MAN.

FEWER THAN 10,000 PAIRS REMAIN.

THE STORKS HAVE BEEN MAKING A COMEBACK LATELY, BUT WITH BURMESE PYTHONS IN THEIR BACKYARD, THE RECOVERY COULD STALL.

YOUNGER, LIGHTWEIGHT PYTHONS ARE EXPERT CLIMBERS.

CHICKS COULD BE SEIZED AND SWALLOWED BY THEM.

A SINGLE SNAKE COULDN'T DEVASTATE A WHOLE COLONY BUT ITS PRESENCE IS WORRISOME.

TO DISCOVER WHETHER PYTHONS POSE A REAL THREAT, SCIENTISTS NEED INGENIOUS SURVEILLANCE TECHNIQUES.

OKAY, YOU WANT TO GO RIGHT OVER IT?

Abraham: THE PYTHON SCIENCE SUPPORT TEAM IS TRACKING WILD SNAKES IN THE NATIONAL PARK.

SOMEWHERE BELOW, THERE'S A SNAKE CARRYING A LOCATOR DEVICE.

MIKE ROCHFORD IS A PYTHON RESEARCHER.

I'VE GOT THE GPS POINT HERE OF THE LAST TIME WE SAW THE SNAKE, AND WE'RE CIRCLING AROUND AND WE'RE GOING TO TRY AND LISTEN FOR THE SIGNAL.

AND ONCE WE START TO HEAR A SIGNAL, WE'RE GOING TO DROP DOWN AND TRY AND PINPOINT THE LOCATION.

Abraham: IT'S A MONUMENTAL TASK.

THE NATIONAL PARK COVERS A VAST 2,500 SQUARE MILES.

Rochford: OKAY, I HEARD THAT SNAKE PRETTY LOUD RIGHT THERE, SO WHAT I DID IS I WENT AHEAD AND TOOK A WAY-POINT, AND THAT WAY WE'VE GOT THE EXACT COORDINATES.

Abraham: THEY'VE ACQUIRED THEIR TARGET.

NOW IT'S TIME TO DROP IN ON THE PYTHON.

IF THEY'RE LUCKY, THEY'LL FIND MORE THAN ONE.

REMARKABLY, THE RESEARCHERS HAVE DISCOVERED THAT TAGGED FEMALE SNAKES CAN LEAD THEM TO OTHER PYTHONS.

THEY'RE HOPING THE ONE THEY'RE TRAILING TODAY WILL BECOME AN INFORMER AND DELIVER OTHER SNAKES INTO THEIR HANDS.

THEY'RE CLOSING IN, BUT WILL THEIR TAGGED PYTHON HAVE OTHERS FOLLOWING HER?

Man: SO MIKE, THIS IS WHERE WE FOUND HER ORIGINALLY, SHE'D MATTED DOWN ALL THIS AREA SO THAT SHE COULD GET UP OUT OF THE WATER AND BASK BETTER.

Abraham: TO LEVEL AN AREA THAT SIZE, THE PYTHON THEY'RE AFTER MUST BE HUGE.

Woman: THAT'D BE THE HOLE!

Rochford: ALL RIGHT.

[ RADIO STATIC, BEEP ] THAT'S WHAT WE LIKE TO HEAR.

YEAH, WE'RE GETTING A GOOD SIGNAL NOW.

Abraham: PYTHONS CAN JUST MELT AWAY INTO THE SURROUNDINGS.

THE TEAM IS JUST YARDS AWAY FROM AN ENORMOUS SNAKE, BUT WITHOUT RADIO-TRACKING, THEY'D NEVER FIND HER.

[ MONITOR BEEPING ] Man: I THINK SHE MAY BE IN THIS MOUND, ACTUALLY.

Rochford: YEP, I SEE HER RIGHT BACK HERE.

Woman: YEP, ALL COILED UP.

Woman: WATCH OUT.

Man: WHOA, WATCH YOUR FEET.

Woman: THERE SHE IS!

Rochford: SHE'S BEHAVING AT THE MOMENT.

SO WE WANT TO GO AHEAD AND LOOK FOR THE SUTURES WHERE WE IMPLANTED THE RADIO TRANSMITTERS.

LOOKS LIKE IT'S HOLDING UP WELL -- WE DON'T HAVE A GAPING WOUND OR ANYTHING LIKE THAT.

OKAY, HERE'S THE SECOND SUTURE RIGHT HERE, AND IT LOOKS LIKE IT'S HEALING UP PRETTY WELL.

SO, LOOKS LIKE SHE'S A HEALTHY SNAKE AND I THINK WE CAN GO AHEAD AND RELEASE HER AGAIN.

Abraham: AT AROUND 15 FEET, THIS IS ONE OF THE BIGGEST WILD SNAKES EVER FOUND IN FLORIDA.

Man: ALL RIGHT, READY?

Abraham: THE TEAM HAS A VERY GOOD REASON FOR LETTING HER GO.

IT'S JUNE, THE BREEDING SEASON.

AT THIS TIME, LARGE FEMALES WILL OFTEN HAVE AN ENTOURAGE.

THE TEAM SOON SPIES A SECOND, SMALLER SNAKE.

Woman: PYTHON!

Man: THERE'S ONE.

Abraham: TWO MALES HAVE BEEN FOUND, NOT FAR FROM THE LARGE FEMALE.

Man: YEAH, THE FEMALE, SHE MUST BE BREEDING IF THERE'S MALES LIKE THIS AROUND.

YOU GOT THAT ONE UNDER CONTROL, THERESA?

Theresa: YEAH.

Rochford: WE GOT ANOTHER ONE OVER HERE.

Abraham: MIKE'S MALE BRINGS THE TOTAL TO THREE, ALL ATTRACTED BY THE PRESENCE OF THE FEMALE.

ALL SET.

Abraham: SHE'S EXPOSED THE SUITORS THAT HAVE COME TO COURT HER.

THE CAPTURED MALES WILL HELP CONFIRM WHAT'S ON THE MENU FOR THESE SNAKES IN FLORIDA.

SKIP SNOW HEADS THE EVERGLADES PYTHON SCIENCE SUPPORT TEAM.

Snow: OKAY, IT'S TIME TO TAKE A LOOK IN THE STOMACH AND THROUGH THE REST OF THE INTESTINES TO SEE WHAT SHE'S BEEN EATING.

Abraham: A PYTHON'S DIGESTIVE TRACT IS NOT COILED LIKE A HUMAN'S -- IT'S EFFECTIVELY THE SAME LENGTH AS THE SNAKE ITSELF.

BY DISSECTING PYTHONS CAUGHT IN THE WILD, SKIP'S MADE MANY FASCINATING DISCOVERIES.

Snow: LOOKS LIKE WE'VE FOUND THE REMAINS OF AN OLD MEAL.

WE HAVE THE REMAINS OF AN ALLIGATOR IN HERE.

CLAWS, OR BONES.

SO, THIS IS THE EIGHTH PYTHON THAT WE HAVE FOUND THAT HAS EATEN AN ALLIGATOR.

THEY ALSO WILL EAT A WIDE VARIETY OF MAMMALS AND BIRDS.

HERE'S THE BILL OF A GREAT BLUE HERON.

THIS IS THE SMALL BILL TIP OF A RAIL.

IN THE MAMMAL CATEGORY, EVERYTHING FROM SMALL MICE AND RODENTS TO BOBCATS.

HERE'S A HALF OF A HOOF FROM ADULT DEER.

SO, AS YOU CAN SEE, THEY EAT A WIDE RANGE OF PREY -- BIRDS, MAMMALS, REPTILES.

Abraham: SO, PYTHONS MUSTN'T REACH AREAS WITH ENDANGERED SPECIES.

THE FLORIDA KEYS.

SO FAR, ONLY A FEW PYTHONS HAVE BEEN FOUND HERE, PROBABLY RELEASED PETS.

A FULL-SCALE INVASION MUST BE AVERTED BECAUSE THIS 100-MILE-LONG ISLAND CHAIN IS THE ONLY HOME ON EARTH FOR THE KEY LARGO WOOD RAT.

U.S. GEOLOGICAL SURVEY BIOLOGIST RON ROZAR HAS A NETWORK OF TRAPS ACROSS KEY LARGO TO INTERCEPT SNAKES ARRIVING FROM THE MAINLAND.

THERE ARE OVER 60 TO BE MONITORED, AND EACH HAS A TEMPTING LURE.

Rozar: SO EACH DAY, WE COME AND WE CHECK THE TRAPS.

CHECK ON, ONE, TO SEE IF THERE'S ANY SNAKES INSIDE, AND, TWO, TO SEE HOW OUR BAIT RAT IS DOING.

NOW WE CHECK ON THIS GUY EVERY DAY, MAKE SURE THAT THEY HAVE ENOUGH FOOD AND MOISTURE.

THIS GUY LOOKS PRETTY GOOD.

NOW THE WAY THIS TRAP OPERATES, SNAKE APPROACHES, SMELLS THE RAT, COMES INTO THE CAGE.

ONCE HE ENTERS THE CAGE, THE FLAPS CLOSE BEHIND HIM SO HE CAN'T GET BACK OUT.

TRIES TO GET TO THE RAT, BUT THE RAT'S IN ITS OWN SEPARATE ENCLOSURE SO THE RAT CAN'T BE GOTTEN TO.

WE THEN EXTRACT THE SNAKE FROM THE TRAP.

SOMETIMES, WE CAN GET ANIMALS IN HERE THAT WE'RE NOT LOOKING FOR, THINGS THAT AREN'T BIG PYTHONS.

SOME OF THE NATIVE ANIMALS THAT MIGHT GO IN HERE INCLUDE WOOD RATS AND COTTON MICE AS WELL AS SOME OF THE NATIVE SNAKES.

FOR THAT, WE'VE PUT IN SOME ESCAPE HATCHES.

SO, IF A NATIVE SNAKE -- FOR INSTANCE A YELLOW RAT SNAKE -- COMES IN HERE, ALL HE DOES, GOES TO THE ESCAPE HATCH, CRAWLS OUT, HE'S SAFE.

Abraham: SO FAR, NO PYTHON HAS MADE IT TO THE TRAP LINE.

BUT WHEN THE INVASION STARTS, THIS WILL BE THE KEYS' FIRST LINE OF DEFENSE.

ALL THIS WORK COULD HELP PROTECT THE ENDANGERED WOOD RAT.

DISNEY'S ANIMAL KINGDOM AND TAMPA'S LOWRY PARK ZOO HAVE SPENT THOUSANDS ON A BREEDING PROGRAM.

GUYS! HELLO, HELLO.

Abraham: THESE CUTE MAMMALS LIVE NOWHERE ELSE.

FEWER THAN 200 OF THEM REMAIN IN THE WILD.

GOOD GIRL.

THE WOOD RAT WAS FIRST LISTED AS THREATENED IN 1969.

SINCE THEN, THEIR POPULATION HAS CONTINUED TO DECLINE.

GOOD GIRL.

Abraham: HUMAN DEVELOPMENTS HAVE SERIOUSLY DEPLETED THE WOODED AREAS THESE RODENTS NEED TO SURVIVE, AND ATTACKS BY FERAL CATS ARE A SERIOUS THREAT.

THE ARRIVAL OF A PYTHON ARMY COULD BE THE FINAL NAIL IN THE WOOD RAT'S COFFIN.

IN CONTRAST, PYTHON POPULATIONS ARE BOOMING.

THE SNAKES ARE INVADING AGRICULTURAL LAND.

WITH ALMOST THREE MILLION ACRES OF IT IN FLORIDA, THERE'S A LOT OF HABITAT FOR THE BURMESE TO COLONIZE.

BUT THESE SEEMINGLY PEACEFUL FIELDS CAN BE DANGEROUS TERRITORY FOR SKULKING SNAKES.

AT PLOWING TIME, THEY RISK BEING DICED BETWEEN SLICING BLADES.

FEW FARMERS ARE SURPRISED TO FIND PYTHONS ON THEIR LAND.

AS THEIR RANGE EXPANDS INTO THE SUBURBS, PYTHONS ARE INCREASINGLY CROSSING PATHS WITH PEOPLE.

AND THEY CAN BECOME A TRAFFIC HAZARD.

DRIVERS NEED TO HAVE THEIR WITS ABOUT THEM.

YOU WOULDN'T EXPECT A SPEED BUMP TO SLITHER.

BUT FLORIDIANS ARE BECOMING ACCUSTOMED TO WEAVING AROUND CREATURES FROM FOREIGN LANDS.

BURMESE PYTHONS ARE JUST ONE OF OVER 400 KINDS OF EXOTIC ANIMALS THAT LIVE WILD IN FLORIDA.

PARROT BIOLOGIST PAUL REILLO LOOKS FOR ONE OF HIS SUBJECTS AROUND THE LUXURY HOTELS OF WEST PALM BEACH.

TO FIND THEM, HE USES TINY REMOTE CAMERAS.

Reillo: OKAY, IN SHE GOES.

THERE WE GO.

YOU KNOW THE GREAT FUN ABOUT THESE NATURAL HOLLOWS IS THAT YOU NEVER KNOW WHAT YOU'RE GOING TO FIND.

OH, THERE WE GO.

WE'VE GOT A DUCK.

HEY, DON'T PECK THE CAMERA!

THAT'S NOT WHAT WE'RE LOOKING FOR.

LET'S SEE WHAT WE'VE GOT IN THIS ONE.

OH, THAT'S NO GOOD, THAT'S NOT WHAT WE WANT.

WE'VE GOT A RACCOON AND THESE GUYS ARE MAJOR PREDATORS OF THE PARROTS.

Abraham: PERHAPS IT'LL BE 'THIRD TIME LUCKY.'

Reillo: OKAY, LET'S SEE WHAT WE HAVE HERE.

WELL THAT'S MUCH BETTER, THAT'S EXACTLY WHAT WE'RE LOOKING FOR, GREEN-CHEEKED AMAZON. THERE ARE THREE BABIES IN THIS NEST AND YOU CAN SEE THAT THEY'RE SITTING ATOP A MOUND OF WRITHING INSECT LARVAE BECAUSE ALL OF THE FOOD GOES IN TO THE NEST CAVITY AND GETS ACCUMULATED AS WASTE.

AND IT BECOMES A BREEDING GROUND FOR INSECTS.

THIS IS AN EXOTIC SPECIES NESTING IN AN EXOTIC TREE HERE IN FLORIDA, BUT THIS FOOTAGE IS VERY USEFUL BECAUSE THIS TECHNOLOGY AND THIS WHOLE RIG IS EXACTLY WHAT WE USE FOR ENDANGERED SPECIES ACROSS THE CARIBBEAN, AND THESE TECHNIQUES THAT WE'RE USING ON THIS SPECIES HERE ARE HELPING US SAVE SIMILAR SPECIES IN THE WILD.

Abraham: IN THEIR MEXICAN HOMELAND, THESE BIRDS ARE THREATENED.

AS FEW AS 3,000 REMAIN.

FLORIDA IS A SAFE HAVEN FOR THEM.

OTHER INVADERS ARE MORE THREATENING THAN THREATENED.

A CARNIVOROUS NILE MONITOR FROM AFRICA.

LIKE THE PYTHONS, THESE GO-ANYWHERE LIZARDS ARE ESCAPEES FROM THE PET TRADE.

THIS ONE'S PICKED UP THE SCENT OF FOOD.

IT'S ON A RAID.

A POND WON'T SLOW IT DOWN.

STRONG SWIMMERS, NILE MONITORS HAVE BEEN FOUND ON ISLANDS TWO MILES OFFSHORE.

THE PREY'S SCENT IS GETTING STRONGER.

SOMEONE'S VALUABLE KOI CARP.

THESE HUNTERS CAN ALSO BE A THREAT TO NATIVE WILDLIFE.

THEY COULD SPELL DISASTER FOR A RARE REPTILE.

NOT AN ALLIGATOR, BUT THE AMERICAN CROCODILE.

IT BREEDS IN SMALL NUMBERS CLOSE TO THE NILE MONITOR'S STRONGHOLD.

FEMALES LAY AROUND 40 EGGS IN LATE SPRING, AND STAY NEAR THE NEST UNTIL THEY HATCH 90 DAYS LATER.

UNLIKE ALLIGATORS, AMERICAN CROCODILES RARELY CHARGE AT INTRUDERS.

THIS ALLOWS MONITOR LIZARDS TO PLUNDER THE NEST WITH IMPUNITY.

THESE ARE INVETERATE EGG THIEVES.

IN THEIR NATIVE AFRICA, THEY ARE MAJOR PREDATORS OF NILE CROCODILE NESTS.

SOME WORRY THAT THEY COULD DIG UP THE EGGS OF FLORIDA'S ENDANGERED MARINE TURTLES.

BUT THERE'S HOPE YET.

A TRAPPING PROGRAM AIMS TO REDUCE THEIR NUMBERS AND PREVENT NATIVE REPTILES FROM HAVING THEIR EGGS SNATCHED.

NOT ALL REPTILE IMMIGRANTS ARE HARMFUL.

A CHARMING LIZARD FROM MADAGASCAR LIVES AND BREEDS IN THE GARDEN OF A POPULAR BAR IN THE FLORIDA KEYS.

THESE LITTLE STUNNERS WERE RELEASED DELIBERATELY BY REPTILE DEALERS WHO COME BACK TO COLLECT ANY SURPLUS LIZARDS TO SELL AS PETS.

FEMALES CAN LAY 12 EGGS EVERY BREEDING SEASON AND THE COLONY HERE IS THRIVING.

SOME OF THE GECKOS ARE EVEN BECOMING LOUNGE LIZARDS.

THEY FACE UNCERTAINTY IN THEIR HOMELAND FROM HABITAT LOSS, BUT PERHAPS THEY'LL MAKE IT IN THE U.S.

ANOTHER LIZARD HAS TAKEN THE STATES BY STORM.

THE GREEN IGUANA.

THESE IGUANAS COME FROM CENTRAL AND SOUTH AMERICA.

BIG MALES CAN GROW OVER 6 FEET LONG.

THEY SOMETIMES FIGHT IN THE BREEDING SEASON.

BUT A BOB OF THE HEAD AND A FLASH OF THE DEWLAP UNDER THE THROAT BY THE LARGEST LIZARD IS USUALLY ENOUGH TO PREVENT COMBAT.

THEY CAN MUNCH THROUGH A BED OF PRIZED BLOOMS IN MINUTES.

THEY ALSO DISLODGE ROOF TILES AND POOP PRODIGIOUSLY.

DESPITE THIS, MOST FLORIDIANS ARE QUITE FOND OF THEM.

THERE ARE OVER 100,000 GREEN IGUANAS HERE.

THE HIGHEST CONCENTRATIONS LIVE ALONG CITY CANALS.

AND THIS IS WHY -- WATER PROVIDES AN ESCAPE ROUTE.

IN AN EFFORT TO STEM THE TIDE OF EXOTIC ANIMALS GONE WILD IN FLORIDA, MIAMI METRO ZOO HOSTS A PET AMNESTY DAY.

SOME PETS WILL OUTGROW THEIR OWNERS, AND THE DAY OFFERS A CHANCE FOR PEOPLE TO TURN THEIR CRITTERS IN.

FISH AND WILDLIFE CONSERVATION OFFICER PATRICK REYNOLDS EXPLAINS.

BASICALLY, IT'S AN OPPORTUNITY FOR PEOPLE TO BRING IN UNWANTED PETS, EXOTIC PETS, PETS THAT OTHERWISE WOULD GET RELEASED INTO THE WILD, LIKE BURMESE PYTHONS, IGUANAS, TORTOISES, UH... EVERYTHING TO A HOWLER MONKEY WAS TURNED IN TODAY.

Man: DO YOU KNOW ABOUT HOW OLD IT IS?

Woman: PROBABLY ABOUT 6.

Man: OKAY.

Woman: SHE LOVES TO BE PETTED.

Abraham: SOME OWNERS HAVE GRADUALLY FALLEN OUT OF LOVE WITH THEIR ANIMALS.

FOR OTHERS, THE DECISION TO GO PET-FREE IS MORE SUDDEN.

Man: I'VE HAD HER FOR 10 YEARS, AND SHE RIPPED MY WIFE'S FINGER OFF THE OTHER DAY.

AND THAT WAS THE END OF THAT!

Abraham: EVENTS SUCH AS THIS COULD HAVE HELPED REDUCE THE SPREAD OF THE BURMESE PYTHON IN RECENT YEARS.

Man: THIS HERE IS A BABY.

BEING AS BEAUTIFUL AS HE IS, THERE WILL BE FIRST PICKS ON HIM, I'M SURE.

Abraham: ALL ANIMALS ARE EXAMINED BY A VET BEFORE BEING TURNED OVER TO NEW OWNERS.

Woman: THESE GUYS NEED A LITTLE HELP.

THIS ISN'T MINOR, SOMEBODY NEEDS TO DEAL WITH THESE GUYS.

Abraham: EVERY ADOPTER HAS TO GO THROUGH AN APPLICATION PROCEDURE.

SOME ARE EVEN INTERVIEWED, TO ENSURE THAT THE AMNESTY ANIMALS GET GOOD, ESCAPE-PROOF HOMES.

SHE'S GOT A RED WOUND INSIDE HER LEFT FRONT FOOT, BUT IT'S VERY SUPERFICIAL.

THE SHELL'S IN PRETTY GOOD SHAPE.

Abraham: IT'S AN EVENT THAT GETS THE WORD OUT AND GETS RESULTS.

SCOTT HARDIN IS FLORIDA FISH AND WILDLIFE CONSERVATION COMMISSION'S EXOTIC SPECIES SECTION LEADER.

Hardin: WE CAN EASILY GET 15 OR 20 BURMESE PYTHONS, THREE OR FOUR RETICULATED PYTHONS.

SOME OF THE OTHER SNAKES THAT REQUIRE PERMITS WE HAVEN'T SEEN YET BECAUSE THEY ARE MORE UNUSUAL IN TRADE, MUCH MORE EXPENSIVE.

BUT BURMESE ARE THE ONLY ONES OUT IN THE EVERGLADES TO OUR KNOWLEDGE, AND THAT'S THE MOST COMMON LARGE CONSTRICTOR.

Abraham: SOME OWNERS DISCOVER THEY CAN'T AFFORD TO FEED AND HOUSE THEIR GIANT SNAKES PROPERLY.

IT'S FAR BETTER THAT THEY HAND THEM IN HERE THAN RELEASE THEM INTO THE WILD.

THE AMNESTIES WILL HELP PREVENT NEW EXOTIC SPECIES FROM COLONIZING FLORIDA.

THEY'LL ALSO HELP STOP FRESH RECRUITS FROM REACHING THE INVADERS THAT ARE ALREADY LIVING WILD HERE, LIKE THE PYTHON.

BUT THE BURMESE INVASION IS WELL-ADVANCED.

BY CATCHING WILD PYTHONS, RESEARCHERS ARE MAKING GOOD PROGRESS IN LEARNING HOW THESE SNAKES LIVE HERE IN FLORIDA.

AND WE KNOW THEY'RE MATING IN THE WILD.

FEMALES HAVE BEEN FOUND WITH SEVERAL MALES.

BUT UNTIL RECENTLY A PYTHON NEST HAD NEVER BEEN FOUND.

VIRTUALLY EVERYTHING WE KNOW ABOUT THE BREEDING HABITS OF BURMESE PYTHONS HAS BEEN LEARNED FROM CAPTIVE SNAKES.

THERE ARE PLENTY OF THOSE IN THIS HUGE FACILITY.

CAREFUL BREEDING CREATES EYE-POPPING PYTHONS.

SOME OF THE MOST FLAMBOYANT CAN BE WORTH TENS OF THOUSANDS OF DOLLARS EACH.

EVERY SPRING, A BURMESE CAN LAY A CLUTCH OF UP TO 100 EGGS.

COILS THAT BROUGHT DEATH TO PREY NOW WRAP PROTECTIVELY AROUND THE EGGS TO KEEP THEM ALIVE.

SHIVERING GENERATES HEAT.

WARMTH FROM TWITCHING MUSCLES CAN RAISE THE EGGS' TEMPERATURE BY AS MUCH AS 11 DEGREES FAHRENHEIT.

SNAKE BREEDERS REMOVE THE EGGS FOR SAFE-KEEPING TO AN INCUBATOR.

IT TAKES TWO MONTHS AT 90 DEGREES FAHRENHEIT TO HATCH THE EGGS.

BUT WHAT HAPPENS IN THE WILD?

UNTIL RECENTLY, NOTHING WAS KNOWN ABOUT HOW OR WHERE BURMESE PYTHONS NESTED IN FLORIDA.

SKIP SNOW'S TEAM CHANGED ALL THAT WITH A STUNNING DISCOVERY.

NEXT TO A BUSY ROAD LESS THAN 17 MILES FROM MIAMI, THEY FOUND A PYTHON NEST.

OKAY, WE'RE HERE AT THE SITE OF A BURMESE PYTHON NEST THAT WE FOUND BACK IN 2008.

THIS IS A SPECIAL CAMERA USED FOR LOOKING IN DENS AND CAVITIES, DEVELOPED TO LOOK IN THE DARK.

WHEN WE DID THIS BACK IN JULY 2008, WE FOUND A FEMALE BROODING ON HER 27 EGGS, WHICH WE'D FIND OUT LATER WHEN WE DUG HER OUT.

IT'S PROBABLY, DON'T KNOW FOR SURE, BUT PROBABLY THE FIRST TIME THAT IT'S BEEN OBSERVED AND FILMED IN THE WILD, AT LEAST CERTAINLY IN THE UNITED STATES.

SO THIS IS PROOF POSITIVE THAT BURMESE PYTHONS ARE BREEDING IN THE EVERGLADES.

Abraham: WHEN PYTHON BABIES LEAVE THE NEST, THEY FACE MANY DANGERS HERE IN FLORIDA.

AT JUST 19 INCHES LONG, THEY'RE VULNERABLE TO ATTACK FROM NATIVE PREDATORS.

A KING SNAKE.

IT SPECIALIZES IN EATING OTHER SNAKES.

THE KING SNAKE IS A CONSTRICTOR, JUST LIKE THE PYTHON.

IT USES MUSCULAR COILS TO SUBDUE ITS PREY.

SURELY THE BABY PYTHON HAS NO CHANCE NOW.

BUT THEN, INEXPLICABLY, THE KING SNAKE ABORTS THE ATTACK.

THIS NEW RECRUIT HAS PASSED ITS FIRST TEST.

A RACCOON -- ANOTHER SNAKE HUNTER.

THE RACCOON'S SHARP TEETH CAN EASILY PIERCE THE HATCHLING'S SKULL.

BUT THE PYTHON HAS A STRIKE UP ITS SLEEVE.

[ SNAKE HISSES ] [ RACCOON CHITTERS ] SOME RECRUITS TO THE PYTHON ARMY MAY SUFFER FATAL INJURIES, BUT THOSE WHO SURVIVE THEIR FIRST TOUR OF DUTY STAND A MUCH BETTER CHANCE OF DEFENDING THEMSELVES.

A SIX-MONTH-OLD PYTHON IS LARGE ENOUGH TO FIGHT OFF ANY RACCOON.

AND AT ONE YEAR OLD, THE RACCOON COULD BE ON THE PYTHON'S MENU.

LARGE PYTHONS ARE INVULNERABLE TO ALL BUT THE BIGGEST ALLIGATORS... AND ONE OTHER HUNTER... US.

THE SOUTH FLORIDA WATER MANAGEMENT DISTRICT EMPLOYS BOB HILL TO WAGE WAR AGAINST INVADERS ON THEIR LAND.

Hill: I'VE PROBABLY FOUND CLOSE TO 75 OR 80 PYTHONS ALONG THIS RIGHT-OF-WAY.

Abraham: BOB KILLS ANY SNAKES HE FINDS.

THEIR BODIES ARE USED TO HELP PYTHON SCIENTISTS ADD TO THEIR KNOWLEDGE OF THESE GIANT SNAKES.

Hill: THIS PYTHON'S ABOUT 9 1/2, 10 FEET LONG.

I'VE CAUGHT PROBABLY 100, 200 SNAKES IN THE AREA WHERE THIS ONE WAS PICKED UP, THE LARGEST ONE BEING ABOUT 16 FEET.

Abraham: SOME AREAS TEEM WITH PYTHONS.

Woman: IN ABOUT A WEEK, WE RECOVERED 54 PYTHONS THAT HAD BEEN KILLED IN ONE SMALL AGRICULTURAL FIELD.

Abraham: SNAKES ARE SPILLING OUT OF THE NATIONAL PARK.

THE ARMY OF SNAKES IS GAINING TERRITORY.

JUST HOW BIG IS THE INVASION FORCE?

WE DON'T KNOW FOR SURE, WE MAY NOT KNOW FOR MANY YEARS, BUT WE DO BELIEVE THAT IT'S ON THE ORDER OF THOUSANDS IF NOT TENS OF THOUSANDS, IT'S NO LONGER JUST HUNDREDS OR A DOZEN.

Abraham: THE ARMY IS GAINING IN SIZE AND STRENGTH.

MORE AND MORE INVADERS ARE BEING SEEN, AND NOT JUST BY SCIENTISTS.

Man: LOOK AT THIS! LOOK AT THAT SNAKE.

Girl: OH, MY GOD!

LOOK AT THAT SNAKE! LET ME GET A PICTURE.

Abraham: IN THE EVERGLADES, BURMESE PYTHONS COULD CAUSE ALL SORTS OF PROBLEMS.

ONE OF THOSE IS COMPETITION WITH OUR NATIVE ANIMALS FOR FOOD.

Abraham: GATORS AND PYTHONS HAVE SIMILAR DIETS.

AS DO ENDANGERED INDIGO SNAKES.

THERE MAY NOT BE ENOUGH TO GO AROUND.

THEY WILL EAT ALMOST ANY ANIMAL OUT THERE, NO MATTER HOW BIG OR SMALL, FROM RODENTS TO ADULT DEER, BOBCATS, BIRDS.

Snow: WE HAVE A NUMBER OF THREATENED AND ENDANGERED SPECIES IN SOUTH FLORIDA THAT ARE POTENTIAL PREY FOR BURMESE PYTHONS.

Abraham: IT COULD MAKE THE DIFFERENCE BETWEEN SURVIVAL AND EXTINCTION.

ANOTHER ONE MAY BE COMPETITION FOR SPACE.

Abraham: PYTHONS TAKE OVER WATERHOLES AND BURROWS THAT WOULD OTHERWISE BE INHABITED BY NATIVE ANIMALS.

ANOTHER ONE CLEARLY THAT WE KNOW VERY LITTLE ABOUT IS DISEASE.

Abraham: PYTHONS MAY HAVE BROUGHT FOREIGN PARASITES WITH THEM, OR AT LEAST ACT AS RESERVOIRS FOR PESTS THAT TRANSFER TO FLORIDIAN REPTILES.

AND LASTLY IS, OBVIOUSLY, SAFETY.

Donlan: THERE'S A GOOD CHANCE THEY MAY LEAVE THE EVERGLADES AND THEY COULD GO ONTO HIGHWAYS AND CAUSE HAZARDS TO TRAFFIC AND HUMANS IN THAT WAY.

Abraham: IN ADDITION TO TRAFFIC ACCIDENTS, THERE IS THAT CHANCE THAT A PYTHON COULD ATTACK A HUMAN.

BURMESE PYTHONS AREN'T KNOWN TO HUNT PEOPLE, BUT THEY DO HAVE THE TOOLS BY WHICH TO KILL PEOPLE, SO WE DO HAVE TO RECOGNIZE THAT THEY ARE POTENTIALLY A HAZARD.

Abraham: SO, ARE PYTHONS HERE TO STAY IN THE EVERGLADES?

AND IF THEY ARE, WILL WE BE SEEING EVEN MORE OF THEM IN THE FUTURE?

Reynolds: WE'RE NEVER GOING TO ERADICATE THEM.

WE DON'T HAVE THE MONEY, THE MANPOWER TO EXTERMINATE BURMESE PYTHONS.

WE HAVE TO LEARN TO LIVE WITH THEM -- THEY'RE WITH US.

WE HAVE A TEAM IN EVERGLADES NATIONAL PARK TRYING TO ERADICATE THEM FROM THE PARK, BUT OUTSIDE OF THE PARK, IN THE CITY, THEY'RE STILL THERE AND THEY'RE PROBABLY ALWAYS GOING TO BE THERE.

THERE'S TOO MANY PLACES FOR THEM TO HIDE.

THE GOAL IS CLEARLY TO CONTAIN THE POPULATION AS WE HAVE IT NOW AND TRY AND KEEP IT FROM SPREADING TO AREAS WHERE IT'S NOT.

HOPEFULLY, AT THE VERY LEAST, WE CAN CONTAIN IT, AND WE CAN SUPPRESS THE IMPACTS THAT THEY MAY HAVE, WHILE WE WAIT FOR A GOOD TECHNIQUE BY WHICH TO ERADICATE THEM.

Abraham: GETTING RID OF PYTHONS IS A FORMIDABLE TASK.

UNTIL THAT HAPPENS, BURMESE PYTHONS COULD BECOME TOURIST ATTRACTIONS.

THESE PREDATORS ARE SO ADAPTABLE, PYTHONS COULD BECOME AS MUCH A PART OF THE EVERGLADES AS ALLIGATORS, MANATEES, BLACK BEARS AND PUMAS.

ONLY TIME WILL TELL.

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