Photo Credit: TimVickers [Public domain], via Wikimedia Commons
Invasive Burmese pythons are feasting on native birds in the Everglades.
Florida's python problem. I'm Bob Hirshon and this is Science Update.
In the late 1970′s, pet Burmese pythons somehow escaped into Florida's Everglades, and they've been breeding there ever since. Among their prey are native birds, which had never dealt with giant snakes before. Smithsonian Institution ornithologist Carla Dove recently examined the stomach contents of dozens of captured pythons.
There were things in there like complete skulls of birds, and feet, and lots of feathers. And so there was enough material present that we could actually get some species identifications.
She identified twenty-five different species, including an endangered wood stork, which stands three and a half feet tall. She says conservationists will have a hard time limiting the pythons' impact—especially if the snakes venture beyond the Everglades. I'm Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
Florida's swampy Everglades make a welcoming home for Burmese pythons. There are low-hanging trees and thick plants to hide in, water for swimming, and lots of prey to catch. Plus, the warm, wet climate is right up their alley. The trouble is, Burmese pythons don't belong in the Everglades. They're native to (you guessed it) Burma (officially called Myanmar), as well as India, southwest China, Bangladesh, Thailand, and other parts of South and Southeast Asia.
Nobody knows exactly how the pythons ended up in the Everglades, but it's safe to assume they were imported as exotic pets, since that's really the only reason they end up in the U.S., apart from zoos, which generally have good control over their animals. (As of July 2010, it is illegal to import the pythons to the United States.) Whether they escaped from their owners or a pet store, or were discarded there when the owners got sick of caring for a giant predatory reptile, remains a mystery. However, since they were first spotted in the early 1970's, their population has grown to thousands, perhaps tens of thousands, of snakes.
The pythons had little to worry about being the new kids on the block. They average twelve feet long, and they're expert hunters of mammals and birds. Some in the Everglades have even been known to eat small alligators. (In fact, a dead python was found in October 2005 with a six-foot alligator in its stomach; the snake had split open, although not necessarily because of the alligator).
The Everglades' native birds, on the other hand, have been easy targets for the pythons. Yes, the birds have long been prey to native alligators, but alligators attack in a very different way than the pythons, which squeeze their prey to death. There are no native constrictor snakes in the Everglades, but pythons aren't the only ones there—other species of giant constrictors, including boas and anacondas, have also been spotted in the area. The prey species had no evolutionary time to develop defenses against the constrictors, so the Everglades has become a giant, all-you-can-eat buffet to the non-native species.
This study of the stomach contents of captured snakes, shows how many different species the pythons have been poaching. That's worrisome not just for Everglades species, but for the surrounding areas as well. Many ecologists say the snakes will inevitably spread beyond the Everglades and into places where people live. In fact, a 2008 study by the U.S. Geological Survey found that climate conditions would be favorable for the exotic snakes to eventually invade a third of the continental U.S., from coast to coast. What's more, this area gets even larger as global climate change warms up the planet. And although officials have introduced hunting seasons and tracking systems to try and control the snakes' population, keeping them all in check is nearly as difficult as putting toothpaste back in the tube.
Now try and answer these questions:
- Why are Burmese pythons and other large constrictors in the Everglades?
- What are the consequences of their introduction to this area?
- What complications may occur in the future?
- What does this say about exotic pets? Should people be allowed to keep pets like these? Why or why not?