The population of Burmese pythons in the Florida Everglades has dropped dramatically in recent years, but the species has already caused lasting damage to native wildlife. Researchers studying the region have documented a severe decline in local mammal populations, and they have identified a parasite carried by the pythons that is now spreading through native snake species on its own.
Trail cameras positioned throughout the southern Everglades have recorded an ecosystem that has become largely empty of its usual animal activity. Data from field researchers shows that raccoon populations in the core affected areas have fallen by more than 99 percent. Opossum numbers are down by nearly 99 percent, and bobcat populations have declined by about 87 percent. The overall mammal population of the southern Everglades has been drastically reduced.

For years, the Burmese python was considered the primary cause. The snakes, which can grow to roughly 20 feet, have been consuming large numbers of native animals. However, researchers noted that the speed and scale of the collapse appeared to exceed what predation alone could explain. Recent observations suggest that the mere presence of pythons has changed the behavior of surviving animals. Many species have stopped moving regularly, altered their breeding patterns, and gone underground to avoid areas where pythons are active.
The pythons originally entered the Florida ecosystem around 1992, when Hurricane Andrew destroyed a reptile breeding facility near the wetlands. Hundreds of young Burmese pythons escaped into the surrounding area. Additional snakes were released by pet owners who could no longer manage them as they grew. The Everglades environment closely resembles the python’s native habitat in Southeast Asia, and the species found an abundance of prey that had no natural defenses against it. Female pythons can lay around 100 eggs at a time, and the population expanded rapidly despite hunting programs and removal efforts.
A secondary problem has emerged in the form of a parasitic worm called Raillietiella orientalis, a lung parasite native to Asia. Burmese pythons carry the worm without showing symptoms, but native Florida snakes have no immunity. When the parasite infects species such as pygmy rattlesnakes and garter snakes, it damages lung tissue and can interfere with breathing. The worms spread through the environment when python waste contaminates the area. Insects consume the waste, frogs eat the insects, and snakes that eat the frogs become infected. The parasite has been detected as far north as Jacksonville, indicating it is moving through native ecosystems independently of the pythons themselves.
One native species, the cottonmouth, appears to tolerate the parasite better than other snakes, though the reasons are not yet fully understood.
In response to the ongoing ecological damage, a coalition of zoos and state agencies has undertaken a reintroduction program for the eastern indigo snake, the longest native snake species in North America. The indigo had disappeared from much of its northern Florida range decades ago due to development and habitat loss. The species feeds on other snakes, including venomous species, and is immune to the venom of American vipers. Captive-bred indigo snakes have been released into the Apalachicola Bluffs region with the hope that they will help control invasive snake populations. Late last year, trail cameras photographed a wild-born hatchling, confirming that the released snakes are breeding successfully in the wild.
There is also evidence that some native predators are adapting to the presence of pythons on their own. Trail camera footage from the Big Cypress National Preserve captured a bobcat attacking a python nest and consuming the eggs. Similar behavior has been recorded in other areas, with bobcats caching python carcasses for later consumption. Alligators have been observed ambushing smaller pythons in the water, and there have been reports of Florida panthers taking down pythons as well.
These developments are considered encouraging signs of what researchers call biotic resistance, the process by which native species gradually learn to prey on an invasive one. However, the scale of the problem remains large, with an estimated 300,000 pythons in the region. The parasite continues to spread, and the reintroduced indigo population is still small. The long-term outcome for the Everglades ecosystem remains uncertain, but the situation is no longer one of passive decline. Native predators are responding, and active management efforts are underway to support the recovery of the region’s wildlife.