Cold Weather and Invasive Species

What's the most effective way to control invasive species? In Florida at least, the answer might be "cold weather."

As reported in the Seattle Times, a cold snap that brought temperatures in the 3o's and 40's had profound impacts on South Florida's non-native fauna: Thousands of non-native fish went belly up, iguanas dropped out of trees and the much-feared pythons were found dead.

(Unfortunately, the frigid temperatures also killed as many as five percent of the native manatees in Florida as well).

Certainly, the cold did not kill all the invasive critters, and over time, populations could become more adapted to cold weather. However, hopefull this puts to rest some of the wilder and more sensational predictions; watch some cable programs, and it has sounded as if pythons would soon be eating children in Central Park.

More importantly, the invasive species die-off raises interesting questions for conservationists. For instance, when are invasive species merely a localized threat? (Certainly continued efforts will be needed to locate pythons in South Florida, but we don't have to worry about them in Idaho).

When will natural factors quickly control populations, reducing the need for costly control measures? What species won't have much effect at all?

Will feral hogs in Idaho remain confined to the Bruneau Valley, or will they spread throughout the state? What invasive species pose the biggest threats to our state?

In a global society, new introductions of plants and animals are inevitable. Currently, many conservationists assume all non-native species are bad. But that is neither strategic nor cost effective. Hopefully, research can help determine where control efforts can have the most effect, and best protect native species and their habitats.

Thanks to writer Steve Bodio's blog for the tip on this story.

Photo: Python and alligator in South Florida, by the National Park Service.