Invasive Burmese pythons may have met their match – opossums

Wildlife researchers have found an unconventional way to help control invasive Burmese pythons in the Florida Everglades – by using one of the snakes’ favorite prey.

Opossums are a key food source for Burmese pythons, which are top predators in the Everglades and have established a permanent breeding population in South Florida, severely harming the ecosystem by wiping out native animals, according to the Conservancy of Southwest Florida.

In 2022, researchers discovered the new technique accidentally while studying the movements and behaviors of small mammals. The team had fitted GPS collars to opossums and raccoons on Florida’s southern coast and discovered an added side effect: They could also track the enormous snakes after they swallowed the tagged animals whole, LiveScience reported.

“We need everything that we can find to remove as many pythons as possible,” Michael Cove, one of the researchers and curator of mammals at the North Carolina Museum of Natural Sciences, told The South Florida Sun-Sentinel in 2023.

With that in mind, Cove, A.J. Sanjar and other researchers expanded the effort to track and euthanize invasive pythons as part of Florida’s conservation work. Here’s how they do it.

How the GPS-collared opossums are tracked

Researchers hope to have at least 40 GPS-collared opossums in their conservation program by later this summer. It’s almost a given that some of these furry creatures will meet their doom in the coils of an invasive python diet in the food chain, the South Florida Sun Sentinel reported.

Although the use of live prey as bait has drawn criticism, the scientists insist that they are researching natural behavior and that the collars do not limit the mammals’ range or raise their risk, but rather use predatory patterns as a means of detection.

“We’re not putting these animals out there and in harm’s way,” Crocodile Lake National Wildlife Refuge manager Jeremy Dixon told the South Florida Sun Sentinel on April 19. “Harm’s way is there. We’re just documenting what’s happening.”

Where Burmese pythons have been reported in Florida

Burmese pythons in the Sunshine State have reduced the population of raccoons by 99%, opossums by 98% and bobcats by 88%, causing a massive ecological collapse in Florida’s Everglades.

A U.S. Geological Survey report shows that Burmese pythons are expanding their range so quickly that it can be marked in miles per year in some areas.

Here’s where they’re most prevalent in Florida:

About the invasive Burmese python

Originally from Southeast Asia, the Burmese python has been introduced to South Florida either through accidental escape or intentional release of captive animals.

In 1979, the first observation of a Burmese python in the wild in South Florida was recorded in Everglades National Park. The heaviest python ever caught in Florida was an 18-foot, 215-pound snake. It was caught by a biologist with the Conservancy of Southwest Florida in Naples in 2022.

How big do pythons get?

The Florida Fish and Wildlife Conservation Commission keeps track of the length and weight of Burmese pythons after sightings are reported. The longest Burmese python ever captured in Florida, in July 2023, measured more than 19 feet.

Since their arrival in Florida, the snakes have brought harmful, non-native parasites and reduced medium-sized mammal numbers by more than 90%, changing the ecosystem, according to the Florida Museum of Natural History.

Source: North Carolina Museum of Natural Sciences, South Florida Sun Sentinel, Popular Science, Florida Fish and Wildlife Conservation Commission, Naples Daily News and USA TODAY research