According to a study published today in the Proceedings of the National Academy of Sciences, ever-proliferating pythons in the Florida Everglades appear to be wiping out large numbers of small mammals.
“In areas where pythons have been established the longest,” reads the report, “mammal populations appear to have been severely reduced.” In some cases, sightings of medium-size mammals are down as much as 99 percent.
For the study, researchers drove 39,000 miles (62,700 kilometers) along Everglades-area roads from 2003 through 2011, counting wildlife spotted along the way and comparing the results with surveys conducted on the same routes in 1996 and 1997.
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.
It might sound like something out of a horror story, but python sightings in the Everglades are all too real. Because they are easy to acquire and can grow to be quite large — in some cases, more than 26 feet long — owners often release them. And then they multiply. Though they are a non-native species, somewhere between 10,000 and 100,000 Burmese pythons are thought to be living in the area.
In 2006, wildlife researchers stumbled upon a 13-foot Burmese python that had apparently died while attempting to eat an alligator. In October 2011, officials were shocked to find a 76-pound, fully intact deer inside the stomach of a python captured and killed in the Everglades. On Christmas, a 13-foot python was discovered in a South Florida family’s swimming pool.
“The effects of declining mammal populations on the overall Everglades ecosystem, which extends well beyond the national park boundaries, are likely profound,” John Willson, a research scientist at Virginia Tech University and co-author of the study, told the Associated Press.
Earlier this month, U.S. Interior Secretary Ken Salazar announced a federal ban on the import of Burmese pythons and three other species of snakes, but environmentalists argue that more needs to be done.