Efforts to control Burmese pythons in the Florida Everglades have expanded beyond the visible predator to address a secondary threat that is spreading more quickly than the snakes themselves. State wildlife managers have hired 25 hunters to capture and remove pythons from South Florida, a program that has removed dozens of snakes in recent weeks. The initiative addresses an invasion that has significantly reduced native mammal populations in the region.
The python infestation in the Everglades dates to the early 1990s. Hurricane Andrew destroyed a reptile breeding facility near the storm’s path in 1992, releasing hundreds of young Burmese pythons into surrounding wetlands. Additional releases by pet owners who could no longer manage the large snakes contributed to the establishment of a wild population. The snakes, which are native to Southeast Asia and can exceed 20 feet in length, found favorable conditions in the Everglades, including warm weather, ample water, and abundant prey.
The ecological impact has been substantial. In areas where pythons have been established longest, wildlife surveys have documented steep declines in mammal populations. Raccoon numbers have fallen by roughly 99 percent, opossums by about 99 percent, and bobcats by approximately 87 percent. Marsh rabbits have largely disappeared from large areas, and white-tailed deer sightings have become rare. Researchers attribute these declines both to direct predation and to changes in prey behavior. Trail cameras have recorded animals avoiding water sources and foraging areas where pythons are present, suggesting that fear of predation is disrupting normal feeding and reproductive patterns.
A second, less visible threat has emerged in recent years. Researchers have found dead native snakes, including pygmy rattlesnakes and garter snakes, with no signs of injury. Necropsies revealed that the snakes were infected with a parasitic lungworm, Rhabdias pseudosphaerocephala, which is native to Southeast Asia and carried by Burmese pythons without harm to them. Florida’s native snakes have no immunity to the parasite, which colonizes the lungs and eventually causes death by respiratory failure. The parasite spreads through the environment via infected prey and waste, and it can survive in regions where pythons cannot. It has been detected as far north as Jacksonville and in central Florida, well beyond the python front.
Wildlife managers have pursued multiple strategies to slow the invasion. In addition to the hired hunters, researchers have used tracking methods to locate breeding females and removed thousands of snakes over the course of the program. Population growth, however, has continued.
In recent years, state agencies have added a new approach: reintroducing the eastern indigo snake, a native predator that disappeared from the Florida panhandle decades ago due to habitat loss and declining gopher tortoise populations. The indigo snake, which can reach nine feet in length, feeds on other snakes and is immune to pit viper venom. Captive-bred indigo snakes have been released in the Apalachicola National Forest, and trail camera footage has confirmed that released snakes are reproducing in the wild. Researchers hope that established indigo populations could target juvenile pythons, creating a barrier to the invasion’s northward spread. The plan carries uncertainties, and results will take time to assess.
Observations from trail cameras in Big Cypress National Preserve suggest that some native predators are adapting to the presence of pythons. Footage has recorded bobcats attacking python nests and consuming eggs, as well as killing juvenile pythons. Alligators have been observed taking pythons in the water, and evidence suggests Florida panthers have also killed pythons on occasion. These behaviors indicate a gradual ecological response to the invasion, though researchers note that such adaptation takes time to develop and spread.
The Everglades remain under significant pressure from the python population and the parasite it carries. While some native species are showing signs of behavioral adaptation, the long-term outcome of the invasion is not yet clear. Wildlife managers continue to monitor the ecosystem and adjust their strategies as new information becomes available.
