Florida's Alien Invaders

One day this summer, Susan Arehart noticed her cat, Luna-tick, acting strangely. Arehart, a transplanted New Yorker who now lives in Riverview, thought maybe the cat was stalking a snake in the yard.

But when she got closer, she saw what was it was: a big, black and white lizard with sharp claws, known as a giant Argentine tegu. She figured it was 4 feet long from the tip of its tail to the end of its forked tongue.

She thought it might run when it saw her. It didn't. "That thing stared me right down," she said. "It's not afraid of anything."

Everyone has heard about the pythons in the Everglades. State officials have told hunters to shoot them on sight. Congress is debating whether to ban their importation. Writer Carl Hiaasen jokes about how he'd like to see politicians out seeking a River of Grass photo op attacked by one.

But Frank Mazzotti, one of Florida's top reptile experts, thinks that what everyone ought to be talking about is the tegu — and also the Nile monitor, the Oustalet's chameleon and several other slithery species that have invaded Florida in recent years.

Unlike the pythons, which are pretty well dug in, Mazzotti said, "we've got 140 species that aren't established yet."

That includes species beyond South Florida — for instance, the tegu, a recent fad in the exotic pet trade. Some tegu owners have reported being surprised at how fast their little lizards grew, and how much they ate.

Five years ago tegus — either escaped captives or those turned loose by irresponsible owners — began popping up in rural and suburban Hillsborough County. On top of frightening homeowners and their pets, tegus eat the eggs and the young of ground-nesting birds and gopher tortoises.

State and federal officials should target those reptiles for removal now, before they get as entrenched as the pythons, said Mazzotti, a University of Florida wildlife ecology professor who has spent more than 25 years studying South Florida reptiles.

"The pythons are just the tip of the iceberg," agreed Steve Johnson, another University of Florida wildlife ecology professor who puts together the online newsletter Invader Updater about non-native invasive fauna. "An early detection network would allow for a more rapid response."

But at this point, Mazzotti said, "there's no money to do risk assessment and early detection." That's too bad, Johnson said, because "by the time we know they're here and established, it's difficult if not impossible to get rid of them."

Instead, most government funding is going toward trying to catch those elusive pythons. Mazzotti said the most effective python-catcher is what he called "the Judas snake," which is a male python outfitted with a radio transmitter and released during mating season to lead scientists to the females. The best catch ever made using a Judas snake, he said, was five females in one day — not a huge haul.

Mazzotti said the only thing that's really made a dent in the python population was last winter's long cold snap.

Mazzotti spent a fairly productive evening in South Florida last week collecting Oustalet's chameleons, voracious eaters which can grow to 2 feet long in their native Madagascar.

"There were more than 100 in a single avocado grove," he said.

Exotic invaders such as the Argentine tegu and the Oustalet's chameleons aren't just a nuisance. Harvard biologist Edward O. Wilson says introduction of alien species is second only to habitat destruction by development and agriculture as the leading cause of extinctions worldwide.

Invaders can wreak such havoc that the National Aeronautic and Space Administration, which has begun mapping the rapid spread of invasive species, has estimated they cost the United States $120 billion each year.

Although tegus have been spotted near Miami and in the Ocala National Forest, eastern Hillsborough County has had the thickest infestation, with 69 reports listed on Johnson's website. They may be attracted by the 500-acre Bell Creek Nature Preserve and the 4,900-acre Balm-Boyette Scrub Preserve, both of which are home to scores of gopher tortoises — and their eggs.

Bobby Hill is convinced all of those reports are "nothing but a crock." Hill runs Varnyard Herps Inc., a Panama City company. "I'm the largest breeder of these animals in the world," he said.

Hill says the tegus can be aggressive if provoked, but usually seek out human affection. He's convinced that while there may be multiple reports of tegus found in the wild, "it's the same animal" being sighted over and over, and not hundreds of them.

"How many Bigfoot reports have there been?" he asked.

Florida's Fish and Wildlife Conservation Commission spends $600,000 a year trying to track and eradicate invasive species like tegus. About $80,000 of that is aimed solely at reptiles. But more invaders show up every day. A study released this month by the University of Florida found more invasive species are making their home in Florida than anywhere else in the world.

That's not news to homeowners in Riverview such as Arehart.

"When I moved to Florida," Arehart said, "I expected seagulls."

Instead, the retired social worker has seen wild boar, coyotes and tegus. She suggested the state needs a new tourism slogan: "Come down to Florida and you can see everything!"

Arehart said she first heard about tegus four years ago when a tree service employee working for a neighbor reported finding "a dinosaur" in some branches. Soon, she said, "little kids walking home from school started taking pictures of them with their cell phones." Now, she said, "they're everywhere."

She's not the only Riverview resident who's freaked out about the big lizards that don't seem afraid of people. One of her neighbors shot one, she said. Another ran one over with a car. She tried doing that too, "but they're just too quick."

For the first time in her life, she's thinking about buying a gun — not for herself, but to protect her cat. Luna-tick keeps crying to go out, but Arehart won't open the door.

"I don't let her out now," she said. "I don't know what's out there."

Times researcher Caryn Baird contributed to this report.

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