Predators in paradise
Burmese python establishing itself in Florida Everglades
By Camille Feanny
and Kimyada Rivers
EVERGLADES NATIONAL PARK, Florida (CNN) -- A dangerous intruder has invaded Everglades National Park, and it's putting the native wildlife at risk.
"We are concerned," park biologist Skip Snow said. "They are competing with other animals for food, space, burrows, crevices and rocks."
The predator in question is the Burmese python. Native to Burma in Southeast Asia, it is one of the largest snake species in the world.
Rangers and other employees have rounded up and removed dozens of pythons from the park since they were first sighted in the late 1990s. Almost 40 have been captured in the last year alone.
But despite those successes, biologists concede that hatchlings have been found deep within the park, and preventing the spread of the pythons will be a long and difficult fight. According to Snow, the animals, which have a 25-year life span, are breeding.
"It's always a problem when a non-native species can sustain and fully establish itself," he said.
For years, the Everglades has struggled to support booming human and wildlife populations that have pushed the ecosystem to the verge of collapse. Wildlife officials say that the python problem is one more struggle that the park did not need.
Global demand for the Burmese python has made the species one of the most popular animals in the multi-billion dollar international pet trade. Experts say that at first, the snakes may seem like a good investment. But by the time the cute hatchling grows from eating small creatures to larger prey, scientists say that many people are not prepared to properly care for the animals.
"People pay as low as $20 per hatchling not realizing how big they grow. In just two to three years, these snakes can grow to be at least 9 feet, so it's a significant commitment" Snow said.
Biologists believe that most of the pythons found in the Everglades were introduced into the park after being discarded by pet owners.
There are few options for owners who want to get rid of of unwanted snakes, biologists say. Most zoos will not take them and although animal shelters try to find other homes for the creatures, most end up being released into the wild.
That's the worst choice possible, Snow said. There are countless examples around the world of invasive predators threatening the health of native species and driving others to the brink of extinction.
Going, going, Guam
One example of the destructive force of invasives played out on the island of Guam, where brown tree snakes have all but silenced the sounds of forest wildlife.
The snakes are believed to have come to the island around World War II, perhaps stowing away in cargo headed to the military base.
Aided by the abundance of prey and absence of natural predators, the snakes now number in the millions. They are responsible for wiping out several species of birds, bats and other native wildlife on the island, and scientists are working earnestly to keep the snakes from spreading to neighboring islands.
They are also consulting with Everglades biologists to help them explore options like traps or snake-sniffing dogs to keep python populations from growing.
Burmese pythons can grow larger than 20 feet (6 meters) long, weigh more than 200 pounds (90 kg), and have the power to overpower a grown man -- though they'd rather opt for more furry food choices like rodents, birds, and rabbits.
They've even been known to dine on other snakes, and biologists say they are equipped to thrive in the Everglades ecosystem. Pythons are extremely agile on the ground or climbing trees, they are excellent swimmers, and the south Florida region shares a similar climate and environment to their native habitat.
The snakes are non-venomous constrictors, and although they don't have fangs they are formidable predators able to ambush and suffocate prey with deadly precision before swallowing their victim whole.
Ecosystem in the balance
Biologists say that the Burmese pythons are just the latest example of a non-native species assuming a stronghold in the Everglades. Previous battles to control exotic plant and animal species have been exhaustive and costly, with no end in sight.
The U.S. Fish and Wildlife Service says invasive species are the primary threat to ecosystems across the nation.
As large a problem as the pythons pose to much of the wildlife, biologists say there is some good news.
They aren't sure how significant the threat to the Everglades' overall ecosystem will be, because unlike Guam, there are predators that will limit the python population -- once-threatened American alligators are now thriving, and native snakes compete with the pythons for food and habitat.
Biologists say that their efforts, along with the natural controls, should keep the snakes from spreading.
But Snow contends that this was a problem that didn't have to happen, and he says that people should think twice before they release unwanted pets into the wild.
"It's against the law, it's bad for the animal and for native wildlife. If you no longer want the animal, find an alternative," Snow said.
CNN Correspondent John Zarrella contributed to this story.