WEST PALM BEACH, Fla. (AP) - A burgeoning population of huge pythons - many of them pets that were turned loose by their owners when they got too big - appears to be wiping out large numbers of raccoons, opossums, bobcats and other mammals in the Everglades, a study says.
The study, published Monday in the Proceedings of the National Academy of Sciences, found that sightings of medium-size mammals are down dramatically - as much as 99 percent, in some cases - in areas where pythons and other large, non-native constrictor snakes are known to be lurking.
Scientists fear the pythons could disrupt the food chain and upset the Everglades' environmental balance in ways difficult to predict.
"The effects of declining mammal populations on the overall Everglades ecosystem, which extends well beyond the national park boundaries, are likely profound," said John Willson, a research scientist at Virginia Tech University and co-author of the study.
For the study, researchers drove 39,000 miles 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.
"The magnitude of these declines underscores the apparent incredible density of pythons in Everglades National Park," said Michael Dorcas, a professor at Davidson College in North Carolina and lead author of the study.
