South Florida cold snap puts squeeze on pythons

Vultures circled over Everglades National Park's Anhinga Trail, where thousands of dead nonnative fish floated in the marshesDead 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 nonnative plants and animals, a January cold snap reminded these intruders that they're not in Burma or Ecuador anymore.

Temperatures in the 30s have apparently killed Burmese pythons, iguanas and other marquee names in the state's invasive species zoo.

"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% fatality on green iguanas. . . . Lots of freshwater fish died; no way to estimate that."

Nonnative fish that have infested the Everglades are turning up dead in the thousands, including the Mayan cichlid, walking catfish and spotfin spiny eel, said David Hallac, chief biologist at Everglades National Park.

No one knows how many Burmese pythons live in the Everglades, where some were released as unwanted pets and others found refuge after hurricanes destroyed their breeding sites. But there are a lot fewer today than there were a month ago.