Pythons in the Everglades have a taste for rabbits, and a new study finds that the invaders' voracious appetites are to blame for pushing native mammals out of large areas of the wetlands.
Some of the Burmese pythons in the Everglades started out as pets that were released or dumped in the wild, creating a thriving python population. The python has become the top predator of marsh rabbits in the snakes' territory, as reported Tuesday in the Proceedings of the Royal Society B.
The Everglades rabbits have steadily been disappearing from python-inhabited areas. To confirm that the invasive snakes are the culprit, researchers moved rabbits from python-free areas of the Everglades into areas where the snakes are found, and used radio trackers with mortality sensors to monitor causes of death.
The giant snakes were the most prolific predators in the Everglades, the study found, responsible for 77 percent of rabbit deaths.
Why It Matters
Mammal populations in the Everglades have dropped drastically since the giant snakes set up home there about 15 years ago. But scientists hadn’t known whether alien predators like the pythons could remove a diverse community of local animals. (See “Pythons Eating Through Everglades Mammals at ‘Astonishing’ Rate?”)
The study’s findings leave little doubt that the pythons have done just that. In fact, they were such dominant hunters that other predators killed only two rabbits in python territory. The pythons killed 17.
It’s likely that the snakes have been just as successful hunting other mammals, such as raccoons, muskrats, and bobcats. This means that other mammalian predators, such as the endangered Florida panther, are left with little to prey upon.
The Big Picture
The pythons—as many as 100,000 of them—have long been thought to pose a serious threat to the Everglades ecosystem. They have voracious appetites in warm weather, and are known to tackle large prey. (See how a python can eat a crocodile.)
One explanation for the pythons’ hunting success is that their prey simply doesn’t know how to cope with giant snakes, which haven’t been a part of their ecosystem for 16 million years.
Florida wildlife authorities remove the snakes when found, and have previously organized competitions like the Python Challenge to control the invasive predators. But nabbing them isn’t easy; the snakes’ dappled skin makes them tough for even trained eyes to spot. (Read about a python hunt that captured 68 snakes.)
With the pythons proving such dominant predators, the study says it’s tough for small mammals to return to territories where the snakes now roam.
Wildlife authorities have tried to control the pythons by not allowing them to be imported or transported over state boundaries. But the snakes are hardy animals, and they’ve been breeding in the wetlands for years. (Read about a giant Burmese python and her eggs.)
So as long as Burmese pythons lurk in the Everglades, the researchers write, it’s unlikely that native mammals will rebound.
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