Biologists at a wildlife research facility in southwest Florida discovered that native predators in the Everglades have begun killing and consuming invasive Burmese pythons, a finding that challenges the long-standing belief that the pythons had no natural enemies in the region.

For years, experts generally agreed that Burmese pythons, which can weigh up to 90 kilograms and reach more than six meters in length, had effectively taken over the Everglades. The snakes, introduced to Florida through the exotic pet trade and released into the wild over several decades, faced no native predators and caused sharp declines in local mammal and bird populations.

The new evidence emerged during a routine tracking study. Researchers had surgically implanted radio transmitters in several young pythons to map their movements and locate breeding females. The transmitters continued to send clear signals, but the snakes themselves disappeared from their usual locations. In some cases, the signals appeared to be coming from inside another animal.

Over the course of one season, three tracked pythons vanished in this manner. When researchers recovered the animals that had swallowed the transmitters, X-rays revealed the remains of the pythons inside them. One recovered animal weighed more than 23 kilograms and measured nearly four meters long.

Camera footage eventually identified the predator responsible for at least some of the disappearances: the Florida cottonmouth, a venomous snake native to the region. The cottonmouth, which typically measures under a meter in length, was recorded swallowing juvenile pythons whole. Researchers noted that cottonmouths have long fed on other snake species, so the behavior is not new, but the addition of pythons to their diet was previously undocumented.

Tracking data also showed that other native animals were preying on pythons. American alligators killed several of the tracked snakes. In 2021, a camera captured a bobcat attacking a python nest, the first such documented event. Owls, hawks, black bears, and Florida panthers have also been observed killing young pythons.

Researchers cautioned that these findings do not mean the python problem is solved. Female pythons lay between 12 and 36 eggs at a time, mature quickly, and live for decades. The sheer number of pythons in the Everglades remains far greater than what native predators can remove. Control efforts by humans, including organized removal programs and hunting competitions, have led to the removal of thousands of snakes, but the population remains large and widespread.

The study’s broader significance, according to the researchers, is that the ecosystem is not as defenseless as previously assumed. Native predators appear to be adapting to the presence of the invasive snakes, and their hunting behavior may be reducing python survival rates in some areas. Whether this pressure will be enough to slow the python population over the long term remains uncertain.