By Barbara Liston
ORLANDO, Florida (Reuters) - Reports that Burmese pythons are devouring almost entire populations of mammals in the Florida Everglades are premature, according to some exotic species experts and a co-author of a widely quoted study.
The idea of pythons annihilating the Everglades made headlines after a January 30 study published in the Proceedings of the National Academy of Science said researches found severe declines in the population of small and mid-sized mammals.
The study presented data supporting its hypothesis that "Burmese pythons have severely reduced populations of several species of formerly common mammals" in the Everglades.
"Do I think we have an impending disaster? I don't think so," said Scott Hardin, exotic species coordinator for the Florida Fish and Wildlife Conservation Commission.
"That study should have never made it to the light of day," said Florida herpetologist Shaw Heflin, known to many as host of National Geographic's "Python Hunters" show. "I don't see anything thus far to point to the fact that these pythons are causing serious harm."
The study compared sightings of animals along park roads before and after the year 2000, which is when the authors say pythons were recognized as being established in the park.
It found a 99.3 percent decrease in observed raccoons and a 98.9 percent decrease in observed opossums, the two most frequently encountered species, as well as decreased sightings of white-tailed deer, bobcats, rabbits and foxes. Sightings of rodents, coyotes and Florida panthers increased.
"The magnitude of these declines underscores the apparent incredible density of pythons in the Everglades National Park," the study concluded.
Everglades National Park spokeswoman Linda Friar said park biologists have "no hard science" demonstrating there has been a dramatic reduction in mammal populations.
Most of the 1.5 million-acre park is inaccessible wilderness.
The size of the python population is unknown with estimates ranging from a few thousand to tens of thousands, according to Friar. Many pythons are believed to have succumbed from the cold during the 2009 and 2010 winters, according to Heflin and Hardin.
Heflin criticizes the authors of the study for failing to fully investigate and dispose of other factors that could account for their observations, including a decade-long drought, cyclical population fluctuations, increased development and pollution.
"There's almost always some other factors going on and certainly in the Everglades, we know that hydrology and water levels plays a huge role in animal abundance," Hardin said.
(Editing by David Adams and Bill Trott)