Everglades snake struggles to gain ground

THE ZEBRA MUSSEL is one of Ireland's most problematic foreign invasive species but be thankful we didn't get the invader that turned Florida's Everglades got - a three-metre python.

Burmese pythons (Python molurus bivittatus) have taken up residence in the far south of Florida and are now thriving in their adopted home. They are fearsome high-end predators and were first detected as a problem when a large Burmese python died attempting to swallow a two-metre alligator. This attempted predation happened more than once.

The US National Parks Service has in recent years joined with academic researchers in monitoring the growing population of python in Florida given its potential catastrophic impact on indigenous and sometimes critically endangered species, animals that have already been recovered from the stomachs of captured P molurus bivittatus.

It is a typical constrictor but it apparently fears nothing and will tackle anything as possible prey, as indicated by its repeated assaults on unsuspecting alligators. Yet it also threatens another top predator, the critically endangered Florida panther, a member of the Puma conclor family.

Wildlife Service staff and researchers now agree that P molurus bivittatus first reached the Everglades as discarded pets, given it is the third most popular species of pet snake being sold in the US. The problem seems to be that the "cuddly" one-metre-long house guest soon grows into something bigger, an entity that might eat the family dog.

Nature will out, and over time snakes abandoned in the Everglades found one another, began to breed and set up a New World outpost far from Burma. Now the Wildlife Service has a major problem on its hands if it is to limit the impact of the python on local fauna.

The US Geological Survey caused a scare earlier this year after the release of "climate maps" which suggested that the python could migrate from Florida, eventually to establish a foothold in up to 32 US states.

This early study has been overtaken however by a new study published this week in the peer-reviewed - free via electronic distribution journal - Public Library of Science. Conducted by climate experts from the City University of New York (Cuny). Its more optimistic conclusion is that the Burmese python will stay where it is and may in time be threatened itself by climate change.

The researchers studied records of P molurus bivittatus distribution in its native range and overlaid this data on high resolution global climate maps. This helped provide them with details of the ideal climatic conditions for the python.

"Combining this climatic data with localities for the Burmese python allows us to create powerful models for predicting suitable habitat for the snakes," says graduate student Alex Pyron, who conducted the study with fellow graduate student Tim Guiher under Dr Frank Burbrink.