Who needs fiction: Alien vs Predator

The following story appeared in the Miami Herald. If you click on the title of this post, you'll be directed to the orignal placement of this story.


Posted on Wed, Oct. 05, 2005
UP FRONT ENVIRONMENT
It's alien versus predator in Glades creature clash

A giant exotic snake's fatal mistake of trying to swallow an alligator has provided scientists with strange new evidence that pythons are continuing to spread in the Everglades.

BY CURTIS MORGANmailto:MORGANcmorgan@herald.com

A meeting between two of the largest and fiercest predators in the Everglades -- a Burmese python and an American alligator -- ended in a scene as rare as it was bizarre.

The 13-foot-snake and six-foot gator both wound up dead, locked so gruesomely it is hard to make heads, tails or any other body part of either creature.

When the carcasses were found last week in an isolated marsh in Everglades National Park, the gator's tail and hind legs protruded from the ruptured gut of a python -- which had swallowed it whole.

As an added touch of the macabre, the snake's head was missing.

For scientists, exactly how the clash occurred is a compelling curiosity. More importantly, the latest and most extraordinary encounter provides disturbing evidence that giant exotic snakes, which can top 20 feet in length and kill by squeezing the life out of prey, have not only invaded the Everglades but could challenge the native gator for a perch atop the food chain.

''It's just off-the-charts absurd to think that this kind of animal, a significant top-of-the-pyramid kind of predator in its native land, is trying to make a living in South Florida,'' said park biologist Skip Snow, who has been tracking the spread of the snakes.

Pythons, likely abandoned by pet owners, have been seen in the Everglades since the 1980s. But in the past two years alone, Snow has documented 156 python captures, a surge that has convinced biologists the snakes are multiplying in the wild.

The growing population of big, scary predators also raises questions about threats to native species and whether anything indigenous -- gators, for starters -- might be capable of consuming and potentially controlling one of the world's largest snake species.

The latest find was spotted floating in a spike rush marsh in the Shark River Slough on Sept. 26 by Michael Barron, a helicopter pilot flying park researchers to tree islands. It was examined the next day by Snow.

The discovery was important for a number of reasons.

LIVING ANYWHERE

For one, it showed the snakes are capable of living anywhere in the Everglades, Snow said. Most earlier finds have been on park fringes, roads or parking lots.

''This is the first we have documented Burmese pythons really in the heart of the slough,'' Snow said.

It also confirmed that snakes and gators, while typically consuming less troublesome mammals, turtles and birds, have an appetite for each other -- at least when the opportunity presents itself.

The first observed encounter in the park occurred three years ago when awestruck onlookers at the popular Anhinga Trail boardwalk witnessed a tussle between a 10- to 15-foot snake and six- to nine-foot gator. That fight, which lasted an estimated 24 hours, ended in an apparent draw, with both swimming off and vanishing.

Earlier this year, Snow documented a gator killing and consuming a python. The latest encounter showed that a hungry adult snake can eat a sizable gator.

Such clashes, though spawned by damaging incursion by an exotic species, can't help but fascinate both the public and scientists, said Frank Mazzotti, a University of Florida wildlife professor and expert on crocodiles and gators in the Glades.

''We've got not only two big things, but two charismatic mega-fauna -- the Burmese python, invader of the Everglades, and the American alligator, monarch of the Everglades,'' he said.

Mazzotti said size would probably dictate which species would win most encounters, and scientists could only speculate why this one ended in double deaths.

Snow's detailed field notes provide some evidence the snake was the attacker -- there were wounds on the gator's head and ''large wads of alligator skin'' in what remained of the snake's digestive tract.

ASKING THE EXPERTS

He was so intrigued that he e-mailed photos and notes to other experts around the country.
So far, several theories abound, none of them pretty and all speculative because once on the scene, Snow quickly abandoned plans to load the bloated, badly decomposed carcasses on the chopper.

''We decided there was no way we were going to do that,'' he said. ``Something was going to go wrong and it was going to be nasty.''

Instead, he performed a ''floating'' necropsy in the water.

While unusual, it's not unheard of for a snake to consume prey that proves too hard or large to digest. Things like claws, hooves or bones can damage the snake's internal organs. The bulk of a victim can put pressure on the snake's lungs, essentially suffocating it from within.

Slowed by the extra weight, the snake might have been attacked by another gator, which could explain a missing python head.

Joe Wasilewski, a South Miami-Dade biologist and expert gator and crocodile tracker, examined the photos and surmised the gator wasn't quite dead when the snake swallowed it snout-first.

That's not uncommon, he said. ''That [gator] could have been kicking its hind legs and ruptured the snake's stomach wall,'' Wasilewski said.

DEAD MOVES

Mazzotti said a similar scenario could have happened even if the gator were dead because of a quirk of its nervous system. Until a gator's spinal cord is severed and literally stirred into jelly with a special tool, he said, ``a dead alligator gives a remarkably good imitation of being alive.

One of the things they do is they move their legs like they're walking. Those claws are pretty sharp. It could tear through the [snake's] skin.''

Mazzotti said it's also plausible the snake scavenged a dead gator. Then time, decay and heat could explain what happened next: a nasty blowout of the snake body.

''You've got a deteriorating carcass, you've got a buildup of gases, you've got sharp claw points . . . ,'' he said.

Snow said a few wags even suggested the deaths were weird enough to fit into the plot of the new TV series Invasion, which involves aliens descending into the Everglades from strange lights during a hurricane.

The carcasses were found a week after the show debuted, he said. ``I've heard some jokes that maybe it was the lights.''

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