Pythons not Florida's only invasive animal problem

Published On: Feb 15 2013 04:08:11 PM EST
KEY LARGO, Fla. -

While hunters stalked the elusive Burmese python through Florida's Everglades over the past month, state and federal wildlife officials set traps for other animals menacing native wildlife in a fragile ecosystem.

The python gets most of the attention in Florida's animal kingdom and is accused of decimating populations of native mammals in the Everglades, but wildlife officials say other species including feral cats, black-and-white tegu lizards and Cuban tree frogs pose equally serious threats.

And while a state-organized Python Challenge was held this year, a Kitty Cat Challenge or Lizard Chase is unlikely. Killing or capturing feral cats would be controversial, and other species lack the daring appeal of pythons.

"A 'Cuban Tree Frog Challenge' wouldn't get anyone excited. I'm saying that in the context of understanding how humans respond to things," said Frank Mazzotti, a University of Florida professor of wildlife ecology who is helping the Florida Fish and Wildlife Conservation Commission with the python hunt.

State wildlife officials say the monthlong python hunt that ended Sunday was a success in raising awareness about invasive species, even though the number of snakes killed idled at 50 in the hunt's last days. The final tally will be announced at an awards ceremony Saturday. Cash prizes will be awarded to the hunters who bagged the longest python and killed the most snakes.

No one knows for sure how many pythons live in the Everglades. Wildlife officials estimate about 10,000 to 100,000, but that's small compared with the several million feral and free-ranging cats believed to be stalking through Florida.

Those cats kill several million wild animals in Florida each year, hunting even when they're regularly fed, state officials say. At particular risk are small mammals and migratory birds that pass through the suburban areas where cats roam. Food laid out for cats also can attract raccoons and other wildlife, which can bring disease or disrupt nearby turtle and bird nests.

For the most part, the state leaves feral cat control to local authorities, some of whom promote managing cat populations through spaying or neutering but still allow the cats to roam.

State and federal officials discourage such trap-neuter-return programs because they don't protect native wildlife. The U.S. Fish and Wildlife Service last month finalized a plan that includes setting traps for cats and other predators in national wildlife refuges in the Florida Keys, where cats are known to pounce on the dwindling populations of two endangered species, the Key Largo wood rat and the Lower Keys marsh rabbit.

Those mammals have lost habitat to development in the Keys, but predation by cats is their highest source of mortality, said Phillip Hughes, an ecologist with the federal wildlife agency in the Florida Keys National Wildlife Refuges Complex, comprising four refuges that stretch from the waters off Key West to where Key Largo meets the Everglades.

"Those cats include cats from people's homes as well as feral and the whole spectrum of free-roaming cats," Hughes said.

"They're preying on some of these vulnerable, small animals at a faster rate than they can replace themselves with."

Native wildlife caught in the traps will be released, but invasive species such as pythons, Nile monitor lizards, armadillos or opossums will be euthanized. Cats that are caught will be transferred to a shelter. Cats elicited far more sympathy and attention in public comments to the plan than other invasive animals.

Overall, Florida is home to more exotic species of amphibians and reptiles than anywhere else in the world, say researchers whose goal is to keep them from becoming so numerous that they're considered established.

It's too late to go after some, such as the Cuban tree frog, because they're too numerous throughout the ecosystem, Mazzotti said.

But it might not be for the tegus, South American lizards that gorge on eggs and invade the burrows of the endangered gopher tortoise. The wildlife commission is working with partner agencies to trap tegus and a handful of other animals, hoping to control or eradicate their populations before they become significant threats.

But other troublesome species are as difficult to spot in the Everglades as the splotchy Burmese python.

"You talk about pythons being the tip of the invasive species iceberg - well, all the fish are under water, so there's no attention paid to their possible spread," Mazzotti said.

Officials say the best solution to Florida's invasive species problems starts long before traps are set or hunts begin. They advocate responsible pet ownership, hold amnesty days for relinquishing exotic animals and encourage people to report sightings to a hotline.

"It's not just about pythons," said Kristen Sommers, head of the wildlife commission's exotic species coordination section. "It's about addressing this holistic view of removing nonnative wildlife from our lands."