Full Breakdown
Invasive Pythons Meet an Unlikely Tracker: Collared Opossums in the Everglades
4/29/2026, 11:16:58 AM
Background: Burmese Python Invasion in South Florida
Burmese pythons, native to Southeast Asia, entered Florida via the exotic-pet trade in the late 1900s. The first wild sighting occurred in Everglades National Park in 1979. Since then the snakes have become top predators, driving medium-sized mammal declines of over 90 %—including raccoons (-99 %), opossums (-98 %) and bobcats (-88 %). They also carry non-native parasites and threaten endangered species.
Methodology: Opossum-Based Tracking
In 2022 researchers discovered that a GPS collar on an opossum continued transmitting after the animal was swallowed by a python. The program now uses VHF trackers with a six-hour mortality sensor; the collar remains functional inside the snake, guiding teams to the predator for removal. Collar cost fell from $1,500 to $190, and each unit can operate up to two years.
Key Personnel & Partnerships
The effort is led by Michael Cove, ecologist at the North Carolina Museum of Natural Sciences, and A.J. Sanjar, technician at Crocodile Lake National Wildlife Refuge in Key Largo, with refuge manager Jeremy Dixon overseeing operations. Funding comes from the South Florida Water Management District.
Results & Statistics
So far 32 opossums have been collared, with a goal of 40 by summer. The method has yielded 18 python removals. The longest recorded python measured over 19 feet in July 2023; the heaviest weighed 215 lb (18 ft) in 2022. The species continues expanding its range at a measurable rate.
Ecological Stakes
Reducing python numbers aims to stop further mammal declines and protect threatened species. The snakes also threaten human safety and pets, consuming meals equal to their own body mass.
Official Statements & Responses
State wildlife officials stress that collars merely document existing predation and do not increase risk. The Florida Fish and Wildlife Conservation Commission highlights rapid detection as essential for removal, while the South Florida Water Management District funds program expansion.
Criticism & Public Concerns
Animal-welfare groups question the ethics of using live opossums as bait, calling the approach a “drop in the bucket.” Researchers reply that opossums already face python predation and that collars do not alter natural behavior.
Verbatim Quotes
- “We need everything that we can find to remove as many pythons as possible.” — Michael Cove, Ecologist, North Carolina Museum of Natural Sciences
- “We’re not putting these animals out there and in harm’s way. Harm’s way is there. We’re just documenting what’s happening.” — Jeremy Dixon, Manager, Crocodile Lake National Wildlife Refuge
- “We modified the collars so that once the mortality switch engages, it locks,” — Michael Cove, Ecologist
- “It's an unfortunate misperception of what we are doing,” — Michael Cove, Ecologist
Future Directions
The team will test the collar system in additional South Florida habitats and aims to have at least 40 collared opossums by summer, improving detection and informing broader invasive-species management.
