Pythons have stranglehold on Florida Everglades ecosystem

Elizabeth Weise
1-30-12
http://www.usatoday.com/tech/science/environment/story/2012-01-30/pythons-florida-everglades/52893342/1

It sounded like a joke when the news first hit in 2000: Giant Burmese pythons were invading the Everglades. Now scientists have measured the real impact of the arrival of this voracious species, and the news is troubling.

In areas where the pythons have established themselves, marsh rabbits and foxes can no longer be found. Sightings of raccoons are down 99.3%, opossums 98.9% and white-tailed deer 94.1%, according to a paper out Monday in the Proceedings of the National Academy of Sciences.

"What if the stock market had declined that much? Think of the adjectives you'd use for that," says Gordon Rodda, an invasive-species specialist with the U.S. Geological Survey (USGS) who published research in 2008 showing that Burmese pythons could conceivably expand across the southern portion of the United States.

"Pythons are wreaking havoc on one of America's most beautiful, treasured and naturally bountiful ecosystems," says USGS Director Marcia McNutt.

Burmese pythons are native to Southeast Asia, but accidental and deliberate release of snakes kept as pets in Florida have allowed them to find a new home there. They can grow up to 16 feet long and weigh up to 150 pounds. The first reports of Burmese pythons in the Florida Everglades began in the 1980s; a breeding population wasn't confirmed there until 2000.

Since then, the numbers of pythons sighted and captured in the Everglades have risen dramatically. According to Linda Friar with Everglades National Park, park personnel have captured or killed 1,825 pythons since 2000.

Now researchers have shown that just as python populations established themselves, the native mammals of the regions began to decline — severely.

People working in the Everglades knew they were seeing fewer mammals, but only when the hard numbers came in was it clear just how devastating the decline has been.

"These were once very common animals in the Everglades, and now they're gone," says Michael Dorcas, a professor of biology at Davidson College in Davidson, N.C., and lead author on the paper.

The pythons aren't a danger to humans. The only known python attacks on humans in Florida have involved snakes kept as at-home pets, says Dorcas, who also authored a recent book, Invasive Pythons in the United States. Now coyotes and Florida panthers are believed to be affected, as well as birds and alligators.

The decrease in mammals is highest where python populations have been established longest, and more mammals are being sighted in areas where the pythons have only recently been documented.

Although scientists can't say conclusively that the decline is a result of python activity, there's good anecdotal evidence. "Last October, we found a 15-foot snake with an 80-pound doe inside it," Dorcas says.

The researchers base their findings on systematic nighttime road surveys done in the Everglades that counted both live and road-killed animals. Ten researchers traveled a total of nearly 39,000 miles from 2003 to 2011 and compared findings with similar surveys conducted in 1996 and 1997.

Mammals in Florida have no natural fear of large snakes because they haven't existed in the area for about 16 million years, when a boa-like snake that used to live there became extinct.

The loss of the mammals is devastating not only to those populations, but to all the animals that rely on them. It's possible that the decline in bobcats, foxes, coyotes and panthers is linked to the disappearance of their typical prey: rabbits, raccoons and opossums.

Pythons also are eating lots of birds. More than 25% of pythons found in the Everglades contain bird remains.

They also happily eat pets, including cats, dogs and some farm animals. Roosters and geese have been found in their stomachs.

And there's not much that can be done. These snakes are "notoriously hard to find and very secretive," Dorcas says. Because much of South Florida is a vast wilderness, the possibility of exterminating or even suppressing them doesn't seem promising, he says. "It's an ecological mess, and exactly what's going to happen down the road remains to be seen."

On Jan. 23, the U.S. Fish and Wildlife Service started the paperwork to ban the importation and interstate transportation of Burmese pythons, northern and southern African pythons and the yellow anaconda because they threaten the Everglades and other sensitive ecosystems.

These snakes are being listed as injurious species under the Lacey Act. Some reptile breeders and collectors, along with Republican lawmakers, argued the restriction constitutes job-killing red tape.

How far the snakes might expand their range is unknown. Research in 2008 showed they could possibly survive across the entire southern United States.

And research this month showed they could survive in saltwater, which had previously been believed to be a barrier to their expansion.

"All of Florida and much of the coastal plain of the southeastern United States is suitable habitat," Dorcas says.

Pythons in Florida Stalked by Hunters and Tourists Alike

http://www.nytimes.com/2010/05/08/us/08pythons.html

Pythons in Florida Stalked by Hunters and Tourists Alike
DAMIEN CAVE
May 7, 2010

FLORIDA CITY, Fla. — Thousands of Burmese pythons, the offspring of former pets, have invaded the Everglades, eating birds, bunnies, even alligators. It has gotten so bad that Congress is considering an outright ban on buying or selling nine kinds of giant snakes.

But an odd thing has happened here in the swamp: the pythons have become celebrities. The snakes are fast becoming an element of Florida lore, attracting “oohs” and “ahhs” from tourists, along with groans from biologists and even python hunters like Bob Freer.

“It’s a little frustrating and very strange,” said Mr. Freer, who figures that his 40 captured pythons — most of which he has euthanized — make him the state’s top private hunter. “They’re asking about pythons that don’t even belong here, instead of alligators.”

Trouble is, the newfound fascination obscures what biologists and Mr. Freer describe as a serious problem. In their view, python proliferation — still significant despite a cold winter that might have killed half the population — is simply the sexiest example of widespread disrespect for pets and the wilderness.

“People need to view exotic species invasions as pollution — biopollution,” said David E. Hallac, chief of biological resources for Everglades and Dry Tortugas National Parks. “In some cases, this form of biopollution can be even more difficult to remedy than chemical pollution, mainly because in most cases, we have no way of cleaning up exotic species from our natural environments.”

Nowhere is the problem more visible than in the open expanse of southwestern Dade County, where tract housing gives way to sawgrass and airboat engines. Mr. Freer, a grandfather who cuts the sleeves off his T-shirts, has lived here for a decade, giving animal presentations to tourists and running a wildlife refuge that doubles as his home.

He grew up in rural New York on a dairy farm with a pet alligator, and he used to live north of Miami with another gator (named Lazy) until his neighbors complained. Now Mr. Freer and his third wife are free to mix with whatever animals they like, and there are plenty.

Near the back of their five-acre property, for instance, sits Rocky, a tiger once owned by a stripper. Buc, an arthritic grizzly bear, lies in a cage next door near the hyenas, Chewy the camel, birds the color of daiquiris, and a lemur from Madagascar whose previous owner pulled out its teeth, so that all its food must now be mashed.

In nearly every case, pet owners gave the animals up or had them taken away by county officials. Pythons, Mr. Freer said, have been part of the mix since the mid-1980s.

“It was very exciting then to think about these giant snakes and being able to find them here in Florida,” he said. “I never really thought there would come a time when you would actually go out and hunt pythons.”

State officials say they had no choice — especially after last July, when an eight-foot python sneaked out of its cage north of Orlando and strangled a 2-year-old. It led to a six-week hunting season to reduce the python population.

“We really wanted the help, and still need it, to get rid of these things,” said Tony Young, a spokesman for the Florida Fish and Wildlife Conservation Commission.

With all the attention, the snakes became bigger stars. Reporters have interviewed officials at Everglades National Park around 300 times. Mr. Freer, meanwhile, has turned up on Animal Planet and the History Channel’s “Monster Quest,” after an episode about the Hillbilly Beast of backwoods Kentucky.

He said that he initially understood the alarm. Pythons are what biologists call “apex predators” that eat nearly everything, including endangered species. And there were financial benefits, too: a group of Canadian snake enthusiasts paid him to help find pythons.

But on a hunting trip in the Southern Glades, a 30,000-acre tract that abuts Everglades National Park, Mr. Freer struggled to shake a sense of melancholy.

The area has become a dumping ground littered with both human ruin — a shuttered fish farm, a closed juvenile detention camp and a former rocket test site — and abandoned animals. In addition to the pythons, Mr. Freer said he had come across cobras and black mambas, emus and ostriches. Since the recession started, he said, he has seen more horses that owners can apparently no longer afford to feed.

The python craze, he said, only illustrated a problem far larger than most people recognize. Mr. Hallac, at Everglades National Park, agreed.

“We have well over a dozen exotic fish that have invaded the park and may pose a threat to our native aquatic organisms,” Mr. Hallac said. “But being that they’re underwater, and not particularly scary to humans, their stories are rarely told.”

At Everglades Alligator Farm, an adventure park where Mr. Freer manages the animals and puts on shows for visitors, python presentations are still a hit. Rangers at the national park are regularly asked about how to avoid or see the famous pythons.

Mr. Freer said he now looked forward to a day when pythons were scrubbed from his routine. “People will be asking me about alligators again,” he said, “And that’ll make me happier.”

A version of this article appeared in print on May 8, 2010, on page A10 of the New York edition.

Pythons could squeeze lower third of USA

http://www.usatoday.com/news/nation/2008-02-20-burmese-pythons_N.htm

Pythons could squeeze lower third of USA
By Elizabeth Weise, USA TODAY

As climate change warms the nation, giant Burmese pythons could colonize one-third of the USA, from San Francisco across the Southwest, Texas and the South and up north along the Virginia coast, according to U.S. Geological Survey maps released Wednesday.

The pythons can be 20 feet long and 250 pounds. They are highly adaptable to new environments.

Two federal agencies — the USGS and the U.S. Fish and Wildlife Service — are investigating the range of nine invasive snakes in Florida, concerned about the danger they now pose to endangered species. The agencies are collecting data to aid in the control of these populations.

They examined Burmese pythons first and, based on where they live in Asia, estimated where they might live here. One map shows where the pythons could live today, an area that expands when scientists use global warming models for 2100.

"We were surprised by the map. It was bigger than we thought it was going to be," says Gordon Rodda, zoologist and lead project researcher. "They are moving northward, there's no question."

Burmese pythons were introduced to the USA as part of the pet trade. The first specimens in the wild were discovered in the mid-1990s in the Florida Everglades, released by owners who no longer wanted them, says Skip Snow, a wildlife biologist with the National Parks Service in the Everglades.

By 2003, there was evidence the snakes had established breeding colonies in the wild. Florida began regulating their sale and ownership Jan. 1.

If federal officials had to worry only about Florida, it would be "decades" before the pythons move into other states, Rodda says. But people keep dumping pythons they don't want into the wild. "We just learned about some that had been released in Arkansas," he says.

The Burmese python is not poisonous and not considered a danger to humans. Attacks on humans have involved pet owners who mishandle and misfeed the snakes, Snow says. In Florida, they eat bobcats, deer, alligators, raccoons, cats, rats, rabbits, muskrats, possum, mice, ducks, egrets, herons and song birds. They grab with their mouth to anchor the prey, then coil around the animal and crush it to death before eating it whole.

If you see one, don't attempt to engage it. Leave the area, note the location and notify the authorities.