Originally Published in the Spring 2013 issue of Rifle & Rod magazine.
An adult deer calmly grazes along the forest floor beneath a secluded grove of trees miles from the nearest human dwelling. All is calm in her world with no real natural predators since she’s much too large for a coyotes to take now as an adult. Her only worry is the occasional man or domestic dog that might give her a scare. But these are her woods, and neither a dog nor a man is a match for her natural ability to smell danger and her incredible camouflage coat which blends so perfectly with her surroundings. What she doesn’t know is a new, exotic predator has entered her habitat and she won’t hear or smell it as it approaches. A Burmese python is silently slithering up behind her, and seconds later the 80-lb. doe is being gradually suffocated by the constricting body of a 17-foot-long super predator. This might seem like footage of African jungles on the National Geographic channel, but the scenario just described actually took place in the Everglades National Park (E.N.P.) in South Florida.
There is now an established population of Burmese Pythons in a 2,000 to 3,000 square mile area below Miami, Florida that could reach the tens of thousands, and maybe even more. The Burmese Python, a sub-species to the Indian Python, is native to Asia and one of the six largest snakes in the world. Adult individuals of this species in their natural habitat average about 12 feet in length, but can grow up to 19 feet. Burmese pythons were originally imported to the United States to be sold as exotic pets.
An established, or breeding population, was first recognized in the 2000s. Herpetologist and snake expert Dr. John Wilson from the University of Arkansas says all of the media linking the snake explosion to Hurricane Andrew in the 90s is probably not sound.
“The press says Hurricane Andrew might have destroyed an exotic pet breeding facility that may have released a bunch of snakes. The data we have found is that probably wasn’t the source of it. The timing doesn’t seem to match up particularly well. The real core population is way down in a very remote area of the Everglades, about 40 miles from the nearest heavily populated area. It seems pretty implausible, that pet breeding facility in Miami could’ve cause this,” said Wilson.
“Surely, large snakes in the wild aren’t commonplace?” you say. Unfortunately, that question remains relatively unanswered. Wilson said the most important task at hand for python researchers is how to calculate an estimated population, so they can then find out how to properly control the problem.
“We have removed between 1,800 to 1,900 pythons in the last five years. But we don’t know if that is a large number of the population or not. Most of those are from the E.N.P. itself. It [the population] is certainly in the thousands, and could be tens or hundred of thousands. Given that so much of that area is completely inaccessible except by airboat or plane – we know there are snakes there but don’t know how many,” said Wilson.
Wilson described the E.N.P. as primarily a huge freshwater marsh with the southern portion having some mangrove portions with a little saltwater intrusion. He said the pythons were doing particularly well in the mangrove habitat and seem to have a very high tolerance of salt water.
There are several contributing factors to the Burmese pythons success as an invasive species in Florida. The most obvious reason for the growing population of pythons is that juvenile Burmese Pythons average about 22 inches in length as a hatchling. Wilson said these juvenile pythons are as large or larger the most native adult snakes in the E.N.P..
“A 22-inch snake doesn’t have many natural predators besides the alligator and is certainly capable of killing small mammals and birds soon after hatching,” said Wilson.
Burmese pythons have another advantage that most native snakes don’t have as well. The average clutch size of a female python is 12 to 36 eggs. In one remarkable case, a 17.5-foot Burmese python caught in the E.N.P. this year had an astounding 87 eggs inside of her at the time of her capture. But, unlike native snakes, female pythons guard their eggs until hatching, giving python hatchlings yet another advantage over native snakes. There’s a pretty slim chance a raccoon or opossum is going to eat the eggs with an adult python laying on top of the nest.
Wilson said an adult python really only has one predator in Florida and that is the American Alligator.
“We have records of alligators eating pythons. We’ve even found skeletons where it seemed that a python and alligators died wrestling each other. But, a really big python would be a big meal for even a big gator,” he said.
So, what does a population of thousands of pythons eat in the wild? The answer is, “Almost every mammal they encounter.” These Burmese pythons are such prolific predators; they have all but wiped out all mammal populations in areas where pythons are present. In a study that was released earlier this year, Wilson described the findings as bleak for native mammals.
“We used [night] road surveys and looked for raccoons, opossums, rabbits and deer. We compared records over time and also from previous road surveys and we saw evidence that the mammals have virtually disappeared in areas inhabited by pythons. In the mid-sized mammals – raccoons, foxes, bobcats, opossums – we saw anywhere from an 85-percent to 100-pecent reduction. With marsh rabbits, which used to be extremely common, there hasn’t been a single sighting in five years,” said Wilson.
In addition to the direct effect on mammal populations due to snakes eating small- to mid-sized mammals and birds. Wilson said there are also the indirect effects of the snakes eating mammals that other native mammals prey on to survive. He said this was particularly threatening in areas of the E.N.P., which are also home to the endangered Florida Panthers.
“Based on the other species we’ve seen pythons eat, we think they could pose a direct threat to panthers as well. We’ve recorded them eating bobcats in Florida, and in native range they can eat leopards. We caught one last December that was 15 feet in length and had a 80-lb. white-tailed deer in its stomach. There’s reason to think pythons aren’t capable of preying on panthers,” said Wilson.
While the efforts to remove individual pythons from the Everglades continue, Wilson said the recent Florida Python Hunting season really had no effect on the population.
“There is a lot of research going on now as starting to find out how we could control them. It’s a long way off if not altogether impossible. The biggest problem is that we know they are quite common, but they are very secretive. There are some areas searched for a daily basis, and we haven’t been able to wipe them out. They just hide too well. We are still figuring out the best ways to catch them. We’re even working with detector dogs right now to improve our ability to find them,” said Wilson.
I know what you’re thinking now. All this talk about big snakes in Florida, but the Everglades are a long way from South Georgia and North Florida. “How does this effect me?” Can, a Burmese python even survive here. Well, the answer is, “Probably.” Dr. Wilson described Burmese pythons as generalists in terms of their habitat preferences.
“In Asia the Burmese Python lives in all different types of habitats. They are found from Thailand and tropical areas, all the way up through southern China, where it is wet, but relatively cool, and India where it is dry. They are also found in the foothills of the Himalayan Mountains where it is not only dry, but also cool. So, they are found in a wide variety of habitats. Though they started in the Everglades in Florida, they are now found in a large variety of habitats, including heavily populated areas,” said Wilson.
Wilson said there’s no way to know for sure, but based on their wide range of habitat climates in their native home of Asia, it is likely that the Burmese python would also be able to survive in South Georgia. Especially in places with little human disturbance like the Okefenokee Swamp.
Senior Wildlife Biologist John Jensen of the Georgia Wildlife Resources Division said that while there are established species of invasive reptiles in Georgia, the Burmese python has yet to make the list.
“ We get reports of some documented exotic snakes, but all we’ve ever been able to find are individuals. These are most commonly escaped or released pets and it is very unlikely that they would find a male or female to reproduce with outside of captivity,” said Jensen.
He said the established species were the brahminy blind snake, which is about 4 inches in length and lives underground, and several species of geckos which are common in the exotic pet trade.
If this established population of pythons were to move north at a rapid rate, are we South Georgians and North Floridians at danger of being attacked by a Burmese python outside our home? Probably not. Dr. Wilson said like alligators, pythons usually avoid contact with humans altogether.
“Pythons in captivity have escaped and killed people, but so far there has not been a confirmed python attack on a person in the Everglades. I tend to think they are similar to alligators. Under most circumstances, they are not hunting people,” said Wilson.
For more information on Dr. Wilson’s research on invasive Burmese pythons and other reptiles, check out his Web page at http://comp.uark.edu/~jwillson/index.html.