by hissing roach » Fri Feb 26, 2010 3:17 pm
Cold Snap Killed Many Pythons In Everglades
Pythons, Iguanas, Non-Native Fish Died In January Freeze Fort Lauderdale Sun-Sentinel 2/11/09
By David Fleshler and Lisa J. Huriash, South Florida Sun-Sentinel
Vultures circled over Everglades National Park's Anhinga Trail, where
thousands of dead non-native fish floated in the marshes.
About half the Burmese pythons found in the park in the past few
weeks were dead.
Dead iguanas have dropped from trees onto patios across South
Florida. And in western Miami-Dade County, three African rock pythons
- powerful constrictors that can kill people - have turned up dead.
Although South Florida's warm, moist climate has nurtured a vast
range of non-native plants and animals, a cold snap last month
reminded these unwanted guests they're not in Burma or Ecuador
anymore.
Temperatures that dropped into the 30s killed Burmese pythons,
iguanas and other marquee names in the state's invasive species zoo.
Although reports so far say the cold has not eliminated any of them,
it has sharply reduced their numbers, which some say may indicate
South Florida is not as welcoming to invaders as originally thought.
"Anecdotally, we might have lost maybe half of the pythons out there
to the cold," said Scott Hardin, the Florida Fish and Wildlife
Conservation Commission's exotic species coordinator. "Iguanas
definitely. From a collection of observations from people, more than
50 percent fatality on green iguanas. Green iguanas really got hit
hard. Lots of freshwater fish died; no way to estimate that."
The cold snap has played into a highly politicized debate over how to
prevent non-native species from colonizing the United States. Reptile
dealers and hobbyists strongly oppose a proposal by the U.S. Fish and
Wildlife Service to ban the import of and interstate trade in Burmese
pythons and several other large snakes. They say South Florida's cold
snap shows these species don't threaten to spread north, as some
claim, and a federal crackdown is unnecessary.
"Pythons are tropical animals," said Andrew Wyatt, president of the
United States Association of Reptile Keepers. "When temperatures fall
below a certain level, they are unable to survive. It reinforces the
idea that the pythons can't exist more than a short period of time
north of Lake Okeechobee. Even the pythons in the Everglades are
dying during the cold snap."
Wyatt said scientists are downplaying the effect of cold weather on
the pythons because that would undermine their ability to win grants
to study a problem that has received international publicity.
"It's all about money," he said. "It's very little to do with the
truth of fundamental problems on the ground."
But federal and state wildlife officials say the cold weather has not
solved the problem. Not only did pythons survive, but so did other
invasive species, even if the cold set them back a bit.
Along the park's Gulf Coast, where old-world climbing ferns lay dense
mats over native trees, the cold snap inflicted frost damage on these
invaders from Asia and Australia, said David Hallac, chief biologist
at Everglades National Park. But it didn't kill them, he said, and
they continue to spread.
And although they receive less publicity than pythons, non-native
fish have infested the Everglades. The cold weather apparently killed
them in the thousands, including the Mayan cichlid, walking catfish
and spotfin spiny eel, Hallac said. But at the bottom of canals and
other water bodies, pockets of warm water allowed some of these fish
to survive, he said, giving them a chance to repopulate the park once
the weather warms up.
No one knows how many Burmese pythons live in the Everglades, where
they were released as unwanted pets or where they found refuge after
hurricanes destroyed their breeding facilities. But what's certain is
there are a lot fewer today than there were a month ago.
Greg Graziani, a police officer who owns a reptile breeding facility,
is one of several licensed python hunters who stalk the snakes in the
Everglades. In four days of snake hunting, he found two dead snakes,
two live ones, and one snake on the verge of death.
"Vultures had pecked through 12 inches by 4 inches down the back of
this animal's body," he said. "I thought it was dead and we reached
down to pick it up and it was very much alive."
In cold weather, Graziani said, pythons go into a catatonic state,
and if they don't make it to a safe place to ride out the weather,
freeze to death. "We're finding the smaller pythons are handling it
better than the large ones - the smaller ones can get into different
cracks and crevices to maintain the temperatures they need."
Joe Wasilewski, of Homestead, a wildlife biologist who hunts pythons
in the Everglades, said that on a single day in late January he found
seven live snakes and seven dead ones.
"You don't see dead ones like that for no reason," he said. "And they
were laid out like they were caught by the onslaught of the cold, the
way the carcasses were lined up."