Pythons are not supposed to be in the Everglades. The snakes likely got there because some Florida creep with way too many pet reptiles let them loose in the Glades in the 1980s. Now the dang things are eating everything and are so unstoppable that the state occasionally encourages random hunters to venture into the slough to wantonly murder as many pythons as possible. Otherwise, the snakes eat native wildlife, including deer and alligators.
As it turns out, a study from the U.S. Geological Survey (USGS) released Tuesday sheds light on why the reptiles have adapted so well to the River of Grass: Some are not full-bred Burmese pythons. Instead, the study suggests a portion of the snake invaders are a cross between the Burmese (Python bivittatus) and its close cousin, the Indian python (Python molurus).
That's an important point, because Burmese pythons tend to prefer wetlands, while Indian pythons thrive on higher ground. Of the 400 python samples the USGS studied, 13 came back as Burmese/Indian crossbreeds. Researchers hypothesize this quality might give some pythons "hybrid vigor," which allows them to take advantage of the most adaptable traits from both species. The USGS guesses the interbreeding likely happened before the snakes even made it into the Glades, so, uh, thanks reptile-weirdo patient zero.
"Hybrid vigor can potentially lead to a better ability to adapt to environmental stressors and changes," USGS researcher Margaret Hunter said yesterday in a news release. "In an invasive population like the Burmese pythons in South Florida, this could result in a broader or more rapid distribution.”
That might answer some basic biological questions that have perplexed Glades researchers for years. Typically, Burmese pythons in their native Asian habitats stay in their wetland confines, but the USGS notes some supposed Burmese pythons in the Everglades have bizarrely been found on drier land. The researchers hypothesize the genes from the Indian python might be helping South Florida's unstoppable snakes adapt to the Everglades even faster.
The USGS also found that the snakes remain closely linked with one another and appear to be inbreeding — it noted the pythons sampled in the data were "midway between first- and second-cousins." Gross.
New Times has covered all sorts of harebrained Glades-python-hunting schemes, from using drones to hunt the snakes to letting celebrity chefs cook pythons as part of a Miami-based Chopped ripoff. Previous studies have noted the snakes are extremely resilient: They can survive in salt water and through unseasonably cold weather and are breeding so successfully that the USGS has tied their rise to a decline in some of the Glades' small-mammal populations, including rabbits. (PETA has asked python hunters to stop decapitating snakes, though.)
The alleged Burmese-Indian python hybrids are also not the only unstoppable invasive species overtaking Florida: Meat-eating tegu lizards, too, are making quick work of the Glades. And in 2015, researchers found a new, hybrid species of invasive "super termites" in South Florida.
The USGS compiled its latest study by taking tissue samples from 400 pythons across South Florida, including sites within Big Cypress National Park, the Florida Keys, and even Southwest Miami-Dade County.
“The snakes in South Florida are physically identifiable as Burmese pythons," the USGS's Hunter said, "but genetically, there seems to be a different, more complicated story.”