Capturing invasive pythons in South Florida

Parkland native Ian Bartoszek does not hesitate to hail Dion the snake as an MVP—“Most Valuable Python.”

After all, thanks to Dion, a “scout” snake, Bartoszek and his fellow biologists at the Conservancy of Southwest Florida removed five Burmese pythons during the last breeding season. “[Dion] had five girlfriends,” Bartoszek jokes.

However, Burmese pythons and their effect on South Florida’s wildlife are no laughing matter. The Burmese python is a large, nonvenomous constrictor that is an invasive species in Florida. You will find them primarily in and around the Everglades ecosystem. The snake represents a threat to native wildlife, but “they’re not interested in us,” Bartoszek says.

One of the snakes captured during this past breeding season was the heaviest Burmese python ever captured in Florida, according to Bartoszek. Specifically, it weighed 215 pounds, measured nearly 18 feet long, and had 122 developing eggs. A necropsy found that an adult white-tailed deer was its last meal.

“Imagine what else she ate over her life[time],” Bartoszek says.

The necropsy, which National Geographic documented, took place in March. Before the December 2021 capture, the largest female removed through the conservancy’s program measured 16 feet and weighed 185 pounds. At the time, it was the heaviest python captured in Florida.

Bartoszek, a 1995 Marjory Stoneman Douglas High School graduate, says that at first, he and his colleagues were unimpressed. “We all underestimated the weight,” says Bartoszek, environmental science project manager for the conservancy’s program. “When we brought her back to the lab and put [her] on the scale, there was a collective wow factor. When we looked, the scale read 215 pounds. We’ve lost count of how many large pythons we’ve captured over the years. To be honest with you, it’s just another big snake for us. There’s always a bigger snake out there.”

Ten years ago, the Conservancy of Southwest Florida started a radio telemetry project to track Burmese pythons in order to learn about their behavior. Since then, Bartoszek and his team removed more than 1,000 pythons collectively weighing more than 26,000 pounds from an area of less than 100 square miles outside of Naples.

Bartoszek and his team use radio transmitters transplanted in male “scout” snakes, such as Dion, to study python movements, breeding behaviors, and habitat use.

Since the conservancy’s python program began in 2013, necropsies have found dozens of white-tailed deer inside Burmese pythons. Also, data researchers at the University of Florida have documented 24 species of mammals, 47 species of birds, and two reptile species in pythons’ stomachs.

The breeding season for Burmese pythons runs from November through March. Last season, Bartoszek and his team removed 4,300 pounds of python from the study area outside of Naples. He says the previous season yielded about the same number.

Removing female pythons plays a large role in disrupting the breeding cycle, Bartoszek says. But that can be easier said than done. Indeed, Burmese pythons are “amazingly cryptic” and hard to locate, he adds. Furthermore, they expand their range each year. Parkland is on the edge of that range, the wildlife scientist says.

The public can report invasive animal sightings by calling 1-888-IVEGOT1. In addition, people can report sightings of invasive species on the IveGot1 app, available at the App store. The app is an integrated invasive species reporting and outreach campaign for Florida that includes the app, a website with direct access to invasive species reporting, and a hotline for instant reports of live animals.

Searching the Woods for Critters

While Bartoszek currently captures huge snakes, he recalled flipping over rocks as a child in the woods in search of critters.

“I always had the bug for turning over stones, seeing where critters were hiding,” he says.

In addition, Bartoszek’s father used to take him fishing. He says those experiences made him appreciate Florida’s wildlife more. As a college student at the University of Arizona, the Parkland native studied wildlife and fisheries science. He recalls coming home from school for the holidays during his college years and appreciating the Everglades and South Florida’s water world even more.

“You have to get away from it to appreciate it sometimes,” Bartoszek says.

After earning his degree, he landed an internship at the Conservancy of Southwest Florida. His responsibilities included working on projects for the Everglades restoration. Also, he recorded wildlife and became more aware of the area’s invasive animal issue. The internship led to Bartoszek’s employment with the conservancy.

Bartoszek says if you told him 11 years ago that he would track one of the largest snakes on the planet, he would not have believed you. He has encountered “some pretty incredible things.”

He says, “You really can’t make this stuff up.”