Naples, FloridaResearchers have captured the most massive python ever recorded in Florida—or anywhere outside its native range, for that matter—weighing 215 pounds and measuring nearly 18 feet in length.
The discovery highlights the persistence of South Florida’s decades-old python problem. Burmese pythons, a reclusive apex predator from Southeast Asia, were introduced to Florida in the 1970s, likely from the exotic pet trade. They’ve been exploding in the wild ever since, altering ecosystems by snacking on a wide variety of native species.
A small, tight-knit team of python trackers at the Conservancy of Southwest Florida in December caught this huge female—whose heft shatters their previous record of 185 pounds—by using a scout snake, a male with a GPS tracker attached. This method lets them find and eradicate more and more snakes, especially big, reproductively active females. Their removal has the promise to help ameliorate the python invasion over time.
When the team first weighed the female, they were near speechless; no one expected that number. “I’m reading 215 pounds,” said Ian Bartoszek, a wildlife biologist and manager of the python project, excitedly. “Wow.”
Another biologist on the team, Ian Easterling, just laughed in disbelief. As intern Kyle Findley recalls, “I thought the scale was broken.”
But the scale was working fine. “That was kind of a line in the sand. We wondered if we’d ever cross 200 pounds,” Bartoszek says. “It raised the bar.”
By finding and dissecting these pythons, researchers are learning more about the serpents, what they eat, and how they may hurt the environment they’ve invaded. I joined them in April as they performed a necropsy on the mammoth female. Afterward, I tagged along to see the scout snake method at work—and accidentally stepped on a python.
Since 2000, Florida Fish & Wildlife has killed or removed over 15,000 pythons, with over 1,000 removed every year beginning in 2017. But scientists have no idea how many thousands more there might be. “That’s the ten-million-dollar question,” Bartoszek says. “We don’t even know the order of magnitude.”
Pythons have persisted because they are masters of stealth. Even for those with training and dedication, the snakes are difficult to find in southern Florida’s vast and densely vegetated wetlands and subtropical forests, all of which are part of or adjacent to the Everglades. (So far, and luckily, the snakes have not been known to establish a wild population outside of this region.)
At the conservancy’s research center in Naples in April, Bartoszek explains how the team gets past this problem.
“The Everglades are a haystack, and these,” Bartoszek says, gesturing to six massive female pythons stretched out on the lab’s floor and table, “are the needles. To find a needle, we use a magnet.”
The magnets are scout pythons like Dionysus, or Dion, a roughly 12-foot-long male, surgically implanted with a transmitter that can be tracked with radio telemetry. The ecologists release the scout snakes into the wild, where they hightail it to reproductive females during breeding season. This year, Bartoszek calls Dion the “MVP”—most valuable python—because it led them to the record-breaking female.
And size matters. “Large reproductive female pythons are very important to remove from these ecosystems,” because they are disproportionately capable of having many offspring, says Sarah Funck, a biologist with the Florida Fish and Wildlife Conservation Commission.
The Conservancy team alone has removed over 1,000 pythons weighing a total of over 25,000 pounds since 2013, the majority being reproductive females, mostly using the scout snake method.
Bartoszek and Easterling monitor their scouts closely during breeding season. When snakes linger suspiciously in one area, they pay the scout a visit, sweeping the dense undergrowth for females. Sometimes, rather than finding a single snake couple, they find a “breeding aggregation,” a chaotic tangle of pythons clamoring to mate.
In December 2021, Dion had been loitering in one area of the western Everglades’ ecosystem outside Naples for several weeks, leading Bartoszek, Easterling, and Findley to suspect that he might be with a female. When they hacked through spiny greenbrier, they were met by the largest python they’d ever laid eyes on.
Easterling and Findley wrestled to try to control the python, who curled up the end of her tail into a tight ball, whipping it around and whizzing past their heads until it “punched” Easterling in the face. After about 20 minutes, the python was exhausted, and they were able to get her into a beige cloth bag, then secured the bag in a plastic tub.
Back at the lab, they lugged the tub onto a scale and registered amazement at the number.
After the python was chemically euthanized under veterinary supervision—one of the toughest parts of the job for the scientists—the team placed its body in one of several freezers, where it stayed until two days before our arrival to witness the necropsy. Kristen Hart, an ecologist with the U.S. Geological Survey Wetland and Aquatic Research Center and a collaborator with the conservancy team, stopped by to see the big female for herself.
“When he opened the freezer,” Hart says, “I definitely had a jaw-dropping moment.”
Guessing at guts
When I arrived at the research center, the snake was out of the freezer, draped in a U-shape on a huge lab bench occupying most of the room. It takes about 48 hours to thaw out a 215-pound python. And the smell does not improve with time.
The biologists carefully run their hands along the python’s lower half, marked with a long black line to guide an incision, feeling for a hint of what could be inside. Soft-spoken and ponytailed, Easterling points out some white stripes on the hide, suggesting the skin had stretched massively to accommodate a girthy meal.
The team has done hundreds of python necropsies, evidenced by their sure, methodical movements—but there’s still a sense of tension in the room. Today, they have two goals: count the follicles, or developing eggs, and see what’s in the gut.
As Easterling slices along the center of the python’s yellow-white belly, a seam slowly opens up, displaying the pink innards. The team pulls open the python’s ribs, revealing a fat layer underneath that resembles garlic cloves vacuum-sealed in blood.
Easterling pokes his finger through a translucent layer of viscera, exposing clusters of what looks like giant egg yolks—egg follicles—just behind a startlingly lime green gallbladder. Farther down, closer to the tail, is the lumpy gray digestive tract and a single gray disk, wrinkled and looking deflated—an old egg that didn’t get laid in a previous year.
Next, Bartoszek and Easterling set about counting the follicles. Ecologists want to know how many eggs a python can lay to accurately model population dynamics; the number of follicles or eggs in a python is a direct indicator of reproductive potential. Big female pythons tend to lay a lot of eggs.
“122 follicles,” Bartoszek announces, after counting twice. “The largest developing egg count, ever.” The record reflects a new known upper limit for reproduction but is not surprising in a python of this size.
“The reproductive potential of these animals is very, very high, and that’s an understatement,” Hart says. And these massive pythons pass on their good genes to many offspring, perpetuating the population’s growth.
Next is the digestive tract. Easterling runs his hands along the tube for a hint of what’s inside. Bartoszek feels what appears to be the front part of a hoof. Findley sprays an optimistically small amount of room freshener.
Easterling slices the tract and begins extruding its contents onto a metal sieve, like rancid sausage meat from its casing. Tan goop with bits of fur and some white lumps—dissolved bone—drop out. Easterling pauses to peer at them.
“Yeah, that’s deer,” he says matter-of-factly. “If you’ve seen enough of these, you learn what they look like.” He keeps extruding; out came the twigs, telling them one meal occurred in a fern patch with greenbrier vines; a couple of python teeth, which is normal; and the real prize of the day, three intact hoof cores.
“This is the double-barrel smoking gun,” Bartoszek says. He views each hoof core as further evidence that pythons are putting pressure on prey bases that native species, such as bobcats and endangered Florida panthers.
To date, 73 animal species (24 mammals, 47 birds, and two reptiles) have been found in Burmese python guts in Florida, as documented by collaborator Christina Romagosa’s team at the University of Florida. Any invasive species can change its ecosystem—an invasive apex predator, especially so.
“These pythons have the ability to totally alter the ecosystem, and I would say they probably already have,” Hart says.
Some ecologists are particularly concerned about the impact pythons could have on the Florida panther, a native and endangered species whose populations the state has been working to revive since 1995. After a nadir of fewer than 20 known panthers in the wild in late 1980s, the Fish and Wildlife Conservation Commission began efforts to breed and rewild panthers, and with some success: Today, there are likely somewhere around 200 Florida panthers, and their wild range appears to be expanding, according to Dave Onorato, a panther ecologist with the Florida Fish and Wildlife Conservation Commission.
More research is needed to know how pythons impact the panthers, Onorato says. “But if pythons start decimating panther prey bases of white-trailed deer, that would start to have an effect on the panthers.” (Learn more: How America’s most endangered cat could help save Florida.)
With so little known about their environmental impacts, every python brought in throughout Florida is an invaluable data point.
State-wide snake hunt
Bartoszek’s team is primed for catching pythons, and though their work has expanded, it’s limited to 100 square miles of the greater Everglades’ ecosystem, a sprawling region that extends across more than 5,000 square miles of southern Florida. Efforts to capture pythons and control their populations rely on collaborations between government agencies including the U.S. Geological Survey and National Park Service, nonprofits like the Naples Zoo Conservation Fund, and philanthropy from individuals around the country.
“The problem is ubiquitous in Florida,” said Kathy Worley, the Conservancy’s director of environmental science. Collaboration and information sharing, she added, are key. “This is going to take a village.”
As part of that collaboration, Bartoszek’s team trains others in the scout snake method. The day after the necropsy, we head into the field to see the technique in action. Easterling and Bartoszek carefully release a 13-foot-long scout snake, Loki, from a cloth bag into a clearing in the palmetto and pine forests of Picayune Strand State Forest, a haven for wildlife outside Naples. We leave Loki, who is angry and hissing, and make our way slowly through dense vegetation, to find MVP Dion. Easterling pushes forward, cutting vines and branches to clear a path, while Bartoszek wields the telemetry receiver and calls out directions.
Gradually, the receiver’s beeping grows louder; we’re close. Easterling crouches down for a look at a moss-covered log I had been standing on moments ago. Sure enough, when Easterling shifts a few bits of soft, disintegrating wood, the python’s telltale pattern is revealed, flashing copper and olive in the dappled jungle sunlight.
“How did we miss that?” Easterling asks rhetorically. But it’s clear—Dion was perfectly hidden inside a rotted log, not a scrap of scales visible. This is what pythons evolved to do: They lurk, unseen, on a game trail in the forest, waiting with seemingly endless patience for an unsuspecting critter to pass.
“He’s a sniper at your feet,” Bartoszek says. “One hundred percent hidden. Undetectable.”
Bartoszek and Easterling enjoy what they do, though it’s physically and mentally draining at times. When they track down one of their scouts or find a female, they’re thrilled—and there are signs the hard work is being rewarded. Already, they’ve seen slower rates of finding massive females, and the scouts tend to lead them to increasingly smaller pythons as the largest are removed.
If all goes well over time, only smaller, younger females will be left, helping control the python population.
But Bartoszek and other biologists are also realistic. Pythons may never be eradicated, but their populations can eventually be controlled.
“We’re trying to put ourselves out of the python-catching business,” Bartoszek says.