Invasion by non-native reptiles and other animals.

University of Florida researchers hold a 162 pound Burmese Python that had recently eaten a 6 foot alligator
the capture took place in 2009 in Florida Everglades National Park.  The sankes have a big appetite for medium sized mamals according to research.  Hence, the decline in numbers of many native species of animals.

"The researchers found staggering declines in animal sightings: a drop of 99.3 percent among raccoons, 98.9 percent for opossums, 94.1 percent for white-tailed deer and 87.5 percent for bobcats. Along roads where python populations are believed to be smaller, declines were lower but still notable.

Rabbits and foxes, which were commonly spotted in 1996 and 1997, were not seen at all in the later counts. Researchers noted slight increases in coyotes, Florida panthers, rodents and other mammals but discounted that finding because so few were spotted overall.

Although scientists cannot definitively say the pythons are killing off the mammals, the snakes are the prime suspect.

In 2010, Florida banned private ownership of Burmese pythons. There is also a federal import ban."

Tens of thousands of Burmese pythons, native to Southeast Asia, are believed to be living in the Everglades, where they thrive in the warm, humid climate... The National Park Service has counted 1,825 Burmese pythons that have been caught in and around Everglades National Park since 2000.


http://www.startribune.com/nation/138367364.html



And from the Washington Post:

Officials can’t stop invasive pythons and anacondas from marauding in the Everglades, Reed said; they can only hope to contain them. “We’re trying to prevent spread to the Florida Keys and elsewhere north.”.. A female python can lay 100 eggs, though 54 is considered the norm...

Andrew Wyatt, president of the Reptile Keepers, which advocates on behalf of snake importers, dismissed the study. “They play fast and loose with facts and make big jumps to conclusions,” Wyatt said. The authors contradict prior studies showing that mercury in the water has played a role in the deaths of small mammals, he said...

The U.S. Fish and Wildlife Service predicted that a new generations of Burmese pythons on the edge of their non-native range can adapt and “expand to colder climates



http://www.washingtonpost.com/national/health-science/in-florida-everglades-pythons-and-anacondas-dominate-food-chain/2012/01/30/gIQAULTVdQ_story.html