In the decades since Burmese pythons became established in the Florida Everglades, the region has seen a documented collapse in many native mammal populations. Recent camera footage from the swamps, however, suggests that the ecosystem is not entirely passive. Researchers are observing signs of native predators adapting to the invasion, alongside ongoing efforts to restore species that were lost long before the python crisis began.
The python’s presence in Florida dates back to the late 20th century. Hurricane Andrew struck South Florida in August 1992, damaging exotic animal facilities near Miami and allowing numerous non-native animals to escape into the surrounding wetlands. At the same time, Burmese pythons were widely sold in the exotic pet trade. Many owners, unprepared for the snakes’ eventual size and strength, released them into the wild along the edges of the Everglades.
The pythons, native to Southeast Asia, found the Florida wetlands highly suitable. They are ambush predators with heat-sensing pits that allow them to hunt in darkness and to submerge themselves in water for extended periods. A single female can produce up to 100 eggs, and with no natural predators present, the population expanded rapidly. Wildlife agencies currently estimate that the python population in South Florida ranges from 100,000 to several hundred thousand.
The ecological impact has been severe. A long-term study by biologists Michael Dorcas and John Wilson, which compared mammal sightings along Everglades roadways, found that raccoon sightings in heavily infested areas fell by over 99 percent, opossum sightings by close to 98 percent, and bobcat numbers declined sharply. Marsh rabbits and foxes became nearly absent from some surveyed areas.
Florida has responded with various removal efforts. The Florida Python Challenge, an annual hunting contest, has generated publicity but typically captures only a few hundred snakes, a small fraction of the total population. Since 2017, the South Florida Water Management District has employed contracted hunters year-round; they have removed more than 20,000 pythons. Thermal imaging drones have proven limited because the snakes’ body temperature often matches their surroundings. The most effective method has been the “Judas snake” technique, in which a captured python is fitted with a radio transmitter and released during breeding season to lead trackers to other pythons.
Researchers have also observed behavioral changes in the pythons themselves. Teams led by Dr. Ian Bartoszek at the Conservancy of Southwest Florida have noted that areas which previously yielded captures have become quieter, suggesting the snakes are either learning to avoid human activity or that more cautious individuals are surviving and reproducing.
The invasion has also introduced a secondary threat. Dr. Christina Romagosa of the University of Florida has studied a parasite native to Southeast Asia, the snake lungworm, which Burmese pythons carry without significant harm. Florida’s native snake species have no resistance to it. The parasite’s lifecycle involves infected pythons shedding waste into water, which is ingested by invertebrates, then passed to frogs, and finally to snakes that eat them. At least 18 native snake species have tested positive, and the parasite is now spreading between native snakes independently of pythons, with cases documented as far north as the Jacksonville area.
One notable finding is that the Florida cottonmouth, a venomous pit viper, has consistently tested negative for the lungworm across multiple surveys. Researchers have not yet identified the cause of this apparent natural resistance, but the finding may have implications for protecting other native species.
Within this complicated picture, there have been developments pointing toward some level of ecosystem recovery. The Eastern indigo snake, the longest native snake species in North America, had declined sharply by the late 1970s as gopher tortoise burrows—which the indigos depend on for shelter—disappeared with the clearing of longleaf pine forests. Conservation programs, including a reintroduction project at the Apalachicola Bluffs and Ravines Preserve, have worked to restore habitat and breed the snakes in captivity. In late 2023, trail cameras captured footage of wild-born Eastern indigo hatchlings in North Florida, the first confirmed wild reproduction in that region in about 50 years.
In Big Cypress National Preserve, researchers have documented native predators attacking pythons. A radio-tagged python was found dead after being killed by a bobcat roughly half its size, and trail cameras have recorded alligators preying on smaller pythons. These encounters do not indicate that native wildlife is controlling the python population, but they do show that the relationship between the invasive species and native animals is not entirely one-sided.
The long-term outcome remains unclear. Python populations continue to expand northward, while Eastern indigo populations are growing slowly from restored areas in the north. The ranges of these species may eventually overlap. Meanwhile, the lungworm parasite is also moving north, which raises questions about whether Eastern indigos will develop resistance or face the same respiratory problems that have affected other native snakes.
The situation in the Everglades is neither a story of sudden collapse nor of imminent recovery. It is a record of an ecosystem under sustained pressure, with an established invasive predator and a parasitic disease that now spreads on its own. It also contains evidence of adaptation: native predators learning to prey on pythons, a native snake species reproducing in the wild for the first time in decades, and a venomous species with an unexplained resistance to a harmful parasite.
Researchers are currently focused on several questions: how to protect native snakes from the lungworm, how to support the expansion of Eastern indigo populations, and how to restore enough habitat to support predator diversity. Some of the most significant work is taking place in laboratories, where biologists are studying cottonmouth blood and tissue samples for clues to their resistance.
Conservation programs continue to work on breeding and releasing Eastern indigos and gopher tortoises, while python removal crews are building detailed knowledge of the landscape and the behavior of the invasive snakes. No one involved in these efforts predicts a simple resolution. The python population is still large, the lungworm is still spreading, and climate change may open new corridors for invasive species. But the recent footage from the swamps shows that the Everglades is not a static environment. It is one that continues to respond, in uneven and often unpredictable ways, to the pressures placed on it.
