how does the burmese python affect the ecosystem?
Snake Facts And Behaviors

How Did the Burmese Python Get into Florida?

The Burmese python is a huge snake that’s normally native to Asia. But, they’ve started to colonize certain areas in Florida. But how did they get there, and how come they’re thriving there, even though they’re thousands of miles away from their natural ecological range?

A small number of Burmese python were set free by irresponsible snake owners who sought to abandon their pets. Hurricane Andrew damaged breeding facilities in 1992, which released several hundred at once. These became a breeding population, which has thrived since.

Scientists and hunters want to cull their population. They’re a major threat to the natural ecosystem of the Everglades, and are putting endangered species at risk. So far, they have had some success, but exact population figures remain unknown. It’s unclear how much work remains to be done.

Burmese Python in Florida Facts

The Burmese python is a very long, heavy constrictor snake. Their scientific name is Python bivittatus, ‘bivittatus’ coming from the Latin for ‘two stripes.’ Rather than being striped snakes, they have dark brown blotches all along their back. These are bordered by black scales, and are on a lighter brown or tan background. The ‘two stripes’ refers to the two stripes on their head, rather than their back.

In their native land, they’re an endangered species. But here in the U.S., they’re a favorite pet. Unfortunately, many snake owners who bought them during their initial popularity realized that they couldn’t take care of one—they grow to longer than 10 feet on average, and can weigh hundreds of pounds. This led to people releasing them to the wild, where they began a breeding population in the Florida Everglades.

Let’s start by looking at how Burmese pythons managed to get all the way from southeast Asia, over to Florida, and how they managed to form a breeding population so far away from home.

Where Did the Burmese Python Originally Come From?

The Burmese python comes from Myanmar. It is sandwiched between Thailand to the south and east, China to the north and east, and Bangladesh/India to the west. It’s a beautiful part of the world, with mountains to the north, the Bay of Bengal to the south, and rainforest and jungle in between. They can be found in ecologically similar regions all across southeast Asia, too (e.g., China, Vietnam, Laos, Thailand and so on).

This is the Burmese python’s natural habitat. They’re semi-aquatic, and need a permanent source of nearby water. Because of the diversity of their geographical range, you can find them in marshes and swamps, hills, woodland, and jungles too. This ability to colonize a variety of habitats, plus their need for water, are what is driving their success here as an invasive species in the U.S.

Are Burmese Pythons Legal in Florida?

Burmese pythons are legal in Florida, so long as you have the correct license for your pet.

Recent additions to the state law of Florida have tightened regulations on animals like the Burmese python. In June 2010, Bill CS/SB 318 passed which amended Chapter 379 of the Florida Statutes. Under the amended section 379.372, many additions were made to the list of animals that can’t be possessed, imported, sold, bartered, traded or bred in Florida without a license from the FWC (Fish and Wildlife Conservation Commission).

How many Burmese pythons are there in Florida?

Under the amended section 379.4015, a minimum fine of $100 applies for keeping one without the correct permit. The animal would also be confiscated. The only exception to these rules is when animals are kept for research, which does require a permit, but the permit is free.

Invasive Species in the Florida Everglades

Florida’s Everglades are a unique ecosystem. But they’re under threat. Not only are people gradually encroaching upon their habitat, but there are many new species that people have introduced there, which don’t belong. These animals are both killing native species, and outcompeting native predators, so that our native wildlife is dying out.

An invasive species is one that isn’t native to an environment, but is introduced to it, and which thrives there. There are many examples from across the world.

There are many dangers that come with introducing a new species to an area:

  • They can predate on a certain kind of plant or animal too much, leading it to extinction
  • They can outcompete with the native plants or animals
  • They can be a danger to people, e.g., by causing road traffic accidents, attacking hikers, etc.
  • They can damage the economy, by eating a particular crop (especially insects.)
  • They can damage the environment in a variety of ways

Burmese pythons are classed as an invasive species in Florida, because they wouldn’t normally be there. But they’re not the only invasive species making a name for themselves.

How Did Burmese Pythons Get to the Everglades?

There are two main theories as to how the initial population started. Towards the end of the twentieth century, sightings of Burmese pythons began—from the late 1980s onwards. This was just as Burmese pythons started taking off as a popular pet, and like all pets, sometimes some are abandoned. All it takes is some nearby pet owners to release their pets, and all of a sudden, you have a small population on your hands.

Now, this wouldn’t have been enough to start the population trends we see today. When there are less than a dozen or so animals of a particular species in the wild, they can’t find each other easily, and therefore can’t mate and carry on the population easily either. But that all changed in 1992 when Hurricane Andrew hit Florida.

Hurricane Andrew caused mass destruction—it was the worst hurricane ever to hit Florida, until Hurricane Irma came along 25 years later. It generated a total of $27.3 billion in damage. What seems to have happened is that Hurricane Andrew damaged local breeding facilities, which let more than a hundred Burmese pythons free, all at once.

Since then, their population has only grown. Because their native habitat is quite similar to the Everglades, they’ve been able to continue breeding ever since. Hunters and scientists have tried their best to limit how many there are in the wild. However, their methods so far have only had a limited impact. Their population is bigger than ever, ironically at a time when their numbers in southeast Asia are decreasing.

How Many Burmese Pythons Are in Florida?

It’s not clear how many Burmese pythons there are in the Everglades. They’re difficult to spot in the undergrowth or hiding in trees, and the Everglades is a big place. As such, all we can do is guess as to how many there are. The U.S. Geological Survey currently believe there to be tens of thousands of Burmese pythons in the Everglades. This number is based on studies in select areas, as well as population trends.

The problem seems to be getting worse, too. In 2018, scientists figured out a way to track down groups of males and females called aggregations. This is where a group of male snakes is all competing for the attention of a nearby female. Scientists captured and released a snake they nicknamed Argo, having fitted him with a tracking chip. They tracked him for a few days before finding him with a 100lb female that was just about to lay her clutch. Releasing him again, three days later, they found him with a 115lb female and seven other males.

What does any of that matter? It shows that the population is only going to grow from this point on unless we do something to stop them.

Why Are Burmese Pythons a Problem to Florida?

Burmese pythons aren’t a ‘problem’ in themselves. They’re just an animal doing what it does best, which is hunting, eating, mating and just plain surviving.

But invasive species, no matter what they are, are a problem. Flora and fauna interact in ways that we don’t fully understand. But what we do understand is that by altering one part of an ecosystem, the rest changes too—and is, perhaps, even destroyed. This is inconceivable to anybody who lives near a national park, or similar protected habitat. Because once it’s gone, it’s gone.

Burmese pythons have so far begun to populate the Florida Everglades, which are quite similar to their native habitat. They’re thriving, and their population is increasing rapidly. At the same time, the Everglades themselves are disappearing. Only 25% of the original Florida Everglades still survives. Politicians have taken steps to protect it, by creating the Everglades National Park. It’s threatened by many issues, including water drainage, nitrates, and mercury entering the ecosystem, urban encroachment, and now invasive species.

How Does the Burmese Python Affect the Ecosystem?

According to a report in the Independent newspaper, Burmese pythons have been responsible for rendering many local species practically extinct. Scientists think that 90 percent or more of the fauna that used to inhabit the Everglades are now gone. That means that there are 90% fewer individual animals living there today than there were since the turn of the century.

They’ve also affected certain animals more so than others. Foxes and rabbits have already disappeared. Raccoons populations are down 99.3%, and opossum populations are down by 98.9%. White-tailed deer have also practically disappeared, with populations 94.1% lower than they were.

If the idea of these animals being wiped out doesn’t bother you, the National Academy of Sciences state that they’re affecting unique species too. In a paper published in 2012, they described how the increase in the number of Burmese pythons was threatening alligators and Florida panthers with extinction too. That’s because once all the prey is gone, it’s not just gone for pythons—it’s gone for the native animals too.

Burmese pythons are also threatening the following endangered/threatened species:

  • Piping plovers
  • Everglades snail kites
  • Wood storks
  • Red-cockaded woodpeckers
  • Coyotes

Burmese pythons feed on 39 endangered species and 41 other rare species. If we don’t act soon, then all of these animals could disappear. In fact, since the population of most of these groups has already been reduced so much, it’s unclear whether there’s much we can do to help them survive.

law on Burmese pythons in Florida

1) Burmese Pythons Are an Apex Predator

Burmese pythons are very large snakes. They can reach upwards of 23 feet, and weigh 200lbs. For reference, that’s as big as a telephone pole. We’re talking about a big predator. This means that they’re bigger than anything else you can find in the Everglades, including alligators.

Besides that, they’re also good hunters. Their natural camouflage prevents prey from being able to spot them. It also stops any predators from being able to find them, including us in our effort to control their population. They can eat almost anything. In 2018, Orland Weekly reported that a Burmese python was found in the process of regurgitating a deer. This in itself isn’t unusual. Deer are the precise kind of prey that a large python can eat, and most snakes regurgitate food they’re trying to eat if a predator comes along to attack them.

But what was special about this Burmese python was that it was trying to eat a snake that was bigger than itself. After they caught the snake, they weighed it—it was 31.5lbs, which isn’t that heavy for a long Burmese python. The deer it was eating (still a fawn) was a hefty 35lbs. That would have been meal enough to last it for weeks.

The point of all this is to say that Burmese pythons can eat almost anything, but there isn’t an animal that can consistently threaten them. Even a crocodile isn’t odds-on to beat a Burmese python in a fight. Because they’re unchallenged, they can keep breeding, and their population keeps growing unchecked.

2) They’re Very Quick Breeders

Burmese pythons are prolific breeders. They can lay 30 or more eggs at a time, and unlike most snakes, protect their eggs from potential threats. This means that they can breed, lay eggs, and have them hatch efficiently and effectively. They can breed every year, between March and April. You can do the math—it hardly takes any time at all for their population to explode.

Not only that, but they start reproducing when they’re very young compared to other animals. They begin breeding from the age of three years old. You can have multiple generations of these snakes within just five years.

The problem is that the upper limit to their population is dictated by how much prey they can find. This is the upper limit of any animal population. This means that the population will keep growing and growing, putting more and more pressure on the populations of prey animals, until the prey animals are all gone. It’s a recipe for disaster.

3) They’re Natural Survivors

So, they have great camouflage. If they can avoid encounters with hunters, a Burmese python in the Everglades can live for fifteen years or more. That’s quite a long lifespan for a snake in the wild as it is. But considering they don’t have any real threats in the Everglades, they can live even longer.

Why is that important? If they can mate every year, or every other year, then a female can have many clutches throughout her life. It’s unclear whether Burmese pythons mate every year in the wild, or take years off, but a female could have several clutches throughout her life. Considering that an average clutch is over 30 eggs, you can see how quickly the population could explode. Just picture if a person you knew could have thirty children every other year—the earth would quickly run out of room!

4) They’ve Interbred to Adapt

Scientists working with the USGS and Everglades National Park have been studying the population there for some time. In 2018, they published something they’d been researching for a while—a study on their DNA, to see how they may have adapted to their new environment, and how they might be different to Burmese pythons back home.

What they found, shocked them. They discovered that many of the Burmese pythons they analyzed had interbred with Indian rock pythons. Of the 400 or so snakes they examined, 13 of them had traces of Indian rock python mitochondrial DNA, which is passed down the mother’s direct ancestral line. They theorized that this hadn’t happened since they’d been living in the Everglades, but had happened at some point in the past when the direct ancestors of these snakes had been in captivity.

Why does that matter? Well, the scientists think that their interbreeding might have made them more adaptable. When two species interbreed, each has a unique set of traits, that make it suitable for living in a particular environment. The offspring of these snakes will inherit the positive traits that help them adapt to their new habitat, while those that can’t adapt will die off. Essentially, it’s natural selection at work.

Unfortunately, this means that interbreeding might have made the Burmese python even better suited to the Everglades.

How Can the Burmese Python Be Controlled?

It’s clear that something has to be done about the Burmese python as an invasive species. If we continue to allow them to roam free, the population will keep getting bigger, threatening more and more local species with extinction. So, what can we do to stop them?

1) Rangers Hunting and Killing Them

It’s the classic argument in favor of hunting. Regular, controlled hunts help keep animal populations in check. While it’s debatable whether this is necessary for some animals like deer, it’s necessary to hunt Burmese pythons and try and prevent their population from growing any more. And that’s exactly what hunters are doing.

According to the National Post, a total of 1,825 Burmese pythons were found and killed between 2000 and 2011. Their news story was related to the biggest ever Burmese python found in Florida, which was 17 feet and 7 inches long. As if that wasn’t testament enough to the success of the invasive species, the snake was a female—and she was pregnant with 87 eggs.

Local authorities have encouraged the hunting and killing of Burmese pythons through bounties. Hunters are paid a flat rate of $8.10 an hour, but they also get a bounty based on the size of the snake they capture. Hunters get $50 for a four-foot snake, plus $25 for each additional foot. So, a ten-foot Burmese python could earn a hunter $200. On top of that, hunters also get $150 for a python that was nesting. 25 full-time hunters are working for local authorities, plus it’s legal for any private individual to join in.

Python bivittatus

If you’re a snake owner or breeder reading this, that might be a little upsetting. But be that as it may, the population in the Everglades has to be controlled, and hunting is a direct method to do just that. Unfortunately, it’s not enough—if it were, then there wouldn’t be any pythons left there, because people have been hunting them for decades now.

2) Radiotelemetry Hunting

Remember what we said above about the snake they fitted with a chip, so they could follow it around and find more snakes? That’s radiotelemetry. Researchers at the University of Florida are working with the USGS, as well as the National Park Service and many other bodies, to control the population of Burmese pythons. They’ve been experimenting with radiotelemetry with great success, as we saw above.

Radiotelemetry helps them track down snakes in small groups. This is of great help to hunters, who can bag five snakes for the price of one. Aside from that, though, the researchers are also using it to learn more about the habitat they prefer, what they eat, and how they’re putting local species at risk. Their approach, quite rightly, is that the more we know about these snakes, the better chance we have of controlling them.

The only downside is that it’s quite a costly way to try and control the population. There’s the cost of the tracker itself. There’s also the fact that you have to repeatedly catch and release the snake, which takes man-hours. If this program could be expanded, it would be highly effective, but costs stand in the way.

3) Regulatory Measures

State legislators have tried to get a handle on the Burmese python problem by passing rules and regulations which should prevent their spread. First, the Florida Fish and Wildlife Commission created a regulation that requires anybody who owns a boa or python longer than 2 inches to have a permit. Owners also have to have their pets tagged so that they can be identified.

The aim is to stop people from buying these snakes when they aren’t ready for them—requiring them to put thought into their purchase, since they would need a license. The tags should also make people think twice about releasing their pets to the wild. Besides that, federal laws have actually made it illegal to import Burmese pythons. They were added to the Lacey Act, which prohibits trade in certain flora and fauna. As a side note, this is actually helpful for the Burmese python—in their natural southeast Asian habitat, their numbers are decreasing.

Aside from this, it’s difficult to think of anything else that the government could do. Ultimately, it’s up to snake owners and potential snake owners to be personally responsible for their actions. A law prohibiting the release of these snakes to the wild, for example, would be ineffective. Who could patrol the Everglades, stopping people in the act of releasing their pets, and arresting them? Unfortunately, it’s logistically impossible.

4) Chemical Control

Chemical control is where we use certain chemicals that are harmful to some wildlife, but not to others, to control them. We use chemicals to protect crops from insects that would eat them if they could. However, chemical control may also be a method of controlling the Burmese python.

Scientists have reviewed the efficacy of acetaminophen in controlling the Burmese python population. Believe it or not, but acetaminophen is actually listed by the U.S. Environmental Protection Agency as a toxicant that kills brown tree snakes. By lacing dead prey with acetaminophen, the snakes are tricked into eating it, and quickly die. Laboratory trials suggest that Burmese pythons are susceptible too!

However, there’s a good reason why using chemical control might not be the best idea. First, it takes quite a lot of acetaminophen to kill a large python. If a non-target species were to eat the prey first—like an alligator—they might ‘take the bullet’ instead. Scientists also have to make sure that endangered native snakes like the Indigo snake don’t eat the prey, for the same reason.

So, while you could no doubt get a few Burmese pythons with this method, you’d be harming native wildlife too. Considering that’s what we’re trying to prevent, this idea doesn’t work in practice. As of yet, there’s no alternative proposal on the table for using chemical controls.

5) Biological Pest Control

Pest control refers to methods of killing an invasive or unwelcome species. It’s possible to use chemicals for pest control, of course, but this has all sorts of unintentional effects on the environment. In a protected area like the Everglades, this isn’t an option.

However, biological pest control is where we use a predator, parasite, fungus or virus to kill off an unwelcome species. The most famous example is from recent history, when in 1995, scientists reintroduced wolves to Yellowstone National Park. They did so to manage the rising elk population, and they were exceptionally successful. Today, the population of wolves is thriving in a previously natural habitat, and the elk are under control.

Scientists examining the problem have reviewed biological control as a potential method of getting rid of Burmese pythons. Perhaps the best idea is to use a virus that specifically affects Burmese pythons, but not native wildlife. Unfortunately, no such control method yet exists. There also aren’t any predators that would fit into the natural ecosystem which could prey on Burmese pythons.

Burmese Python FAQs

There are a few solutions that are most people’s first reactions to the Burmese python invasive species problem. Unfortunately, there are good reasons why they aren’t workable options.

Why can’t we ship them back to Asia?

So, Burmese pythons are critically endangered in some parts of their natural habitat. This led to local authorities preventing their capture and export. Because their numbers are decreasing, surely it would make sense to ship them back to Asia? We could organize a huge hunt, capturing hundreds or even thousands of them, and sending them back where they came from?

Unfortunately, it just wouldn’t work. Even though they’ve only been here for thirty years or so, Everglades Burmese pythons are different to the original Burmese pythons back home. They have immunities to all of the bacteria and viruses that you would find in the Everglades, but not those from southeast Asia.

This means that if you reintroduced these pythons to southeast Asia, they would die off quite quickly because they aren’t immune to the bacteria and viruses they’d find there. And at the same time, the Everglades pythons would introduce all sorts of new viruses to their Asian cousins who aren’t immune. You would be killing both populations. So, no, you can’t just ship them back.

Could we capture them all and keep them as pets?

This isn’t the worst idea. You’re legally free to hunt Burmese pythons in the Everglades. If you do, and you decide to keep it, that’s not against the law so long as you have a license. You would be reducing the numbers in the wild, and if it’s something you’re concerned about, it’s also more humane than hunting and killing them.

Unfortunately, it’s not the perfect solution either. Wild-caught snakes don’t adjust well to living in captivity. They’re typically more aggressive, less likely to feed on what you offer them, and more likely to die young from a variety of factors. So it wouldn’t be a pleasant experience.

Besides that, it’s also not fast-acting enough. There are tens of thousands loose in the wild, so unless we could physically catch every single one, the population will bounce back. And because there are so many of them, the market would be saturated. There aren’t enough people out there that want to own a Burmese python to house them all. Capturing them isn’t a bad idea, it’s just not effective enough.

Could we capture them and eat them?

Snake meat is edible. It’s a delicacy in China. Besides that, snakeskin is a valuable commodity. That’s part of the reason why they’re critically endangered in some parts of their range. If you were to go out and catch a Burmese python in the Everglades, you could, essentially, do what you want with it. You could eat it if you like. But it seems like this idea isn’t appealing to enough people to get them out hunting them.

Regarding making money from them, you already make money from catching and killing them. Some hunters are paid both an hourly wage and a bounty for every snake they catch. They then hand the snake into the local authorities. It would hypothetically be possible to sell the snakeskin rather than hand it in as a bounty, but you wouldn’t earn more than you would from the bounty. You would also have to find somebody to sell it to, which might be difficult.

So again, while these things might offer small incentives, they aren’t enough to push the population down significantly. That is the story of it all. While scientists are making strides toward understanding how the population is doing so well, we’re still some distance from an effective, long-term solution. If we don’t hurry up, the Everglades as we know them might disappear forever.