For millennia, the pristine Everglades had been suspended in ecological harmony, forming a marshland ecosystem home to unique organisms found nowhere else on Earth -- but the presence of uninvited predators is threatening to irrevocably tip the balance. Over the last decade, National Park officials have noted a dramatic increase in the number of invasive pythons in the Everglades, as some have grown to as much as 16-feet long by feeding on the region's protected animals.
In all, officials estimate there to be tens-of-thousands of pythons in the Everglades -- and it is believed that most of the snakes, a species native to the Old World, found their way into the national park after growing up in captivity as pets, or being loosed from zoos during hurricanes in the 1990s. But for as humble as their beginnings may have been, many of the pythons have grown to be giant killers capable of wreaking havoc on native species, reports the Christian Science Monitor.
A study which conducted a census of Everglade animals during the pre-python invasion era in the 1990s suggested a remarkable decline has taken place in more recent years:
In areas where pythons had been present the longest, between 2003 and 2011, populations of raccoons dropped 99.3 percent, opossums 98.9 percent and bobcats 87.5 percent. Marsh and cottontail rabbits, as well as foxes, though common before the pythons were seen in the area, were not seen at all in these surveys.
In areas where pythons had recently taken root, the mammal decreases were smaller; in areas where pythons hadn't been spotted mammal numbers were similar to those in the Everglades' pre-python years.
Earlier this month, the U.S. Fish and Wildlife Service enacted a ban on the importation of pythons and other possibly predatory snakes in the United States in hopes of curbing the decline of native wildlife, though some say that it may already be too late to fully recover some of the Everglades's species to natural levels.