EVERGLADES NATIONAL PARK, FLA. - "SNAKE!" Skip Snow slammed on the brakes. When the off-roader plowed to a halt, he and his partner, Lori Oberhofer, leaped out and took off running toward a pair of 10-foot Burmese pythons lying on a levee.

Snow, a wildlife biologist, grabbed one of the creatures by the tail. The python, Oberhofer says, did not care much for that.

"It made a sound like Darth Vader breathing," she said, "and then its head swung around, and I saw this white mouth flying through the air."

Snow saw the mouth, too -- jaws open 180 degrees, gums an obscene white, needle-sharp teeth bared. He let out a shriek, then blinked, and when his eyes opened, the python's head was hanging in mid-air, less than a foot from his own. Oberhofer, with a Ninja-like thrust, had snared the python in mid-strike.

Both snakes were bagged, trucked off to the Everglades Research Center, euthanized and necropsied -- meaning their innards were dissected, then meticulously inspected, for the benefit of science.

So goes python control in the Everglades, a painstaking slog against a voracious foreign species that has established a stronghold in the watery wilderness and put native wildlife at risk.

Critters that pythons find most delectable -- raccoons, opossums, muskrats and native cotton rats -- are under attack, as are birds such as the house wren, pied-billed grebe, white ibis and limpkin.

Scientists also worry that these slithery giants -- which have been known to grow as long as 26 feet -- may soon start to feast on native species whose survival is in doubt.

A decade ago, Snow and Oberhofer spent their days reintroducing rare, native birds to the pinelands and monitoring "indicator" species, such as wading birds, alligators, bald eagles, panthers. Then, in the late '90s, pythons began turning up -- cast-offs from the global trade in exotic animals as pets.

As vast and threatening as the wetlands may appear, they have been so abused by humans in the last century that a population of pythons, if left unchallenged, could take down the fragile web of life within a generation.

"It's a now-or-never thing," Oberhofer said. "We still have a chance, with the python's numbers being so limited, to do something. But if we let this go, we don't know how far the pythons will migrate, how much they will reproduce."

One thing is certain, Snow said. "They'll eat just about everything that's warm-blooded."