Pythons apparently wiping out Everglades mammals

Jan 30, 2012 By MATT SEDENSKY , Associated Press
In this November 14, 2009 photo provided by the University of Florida, University of Florida researchers hold a 162-pound Burmese python captured in Everglades National Park, Fla. Therese Walters, left, Alex Wolf and Michael R. Rochford, right, are holding the 15-foot snake shortly after the python ate a six-foot American alligator. The National Academy of Science report released Monday, Jan. 30, 2012, indicates that the proliferation of pythons coincides with a sharp decrease of mammals in the park. (AP Photo/ University of Florida, Michael R. Rochford)

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 , found that sightings of medium-size mammals are down dramatically - as much as 99 percent, in some cases - in areas where 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.

Tens of thousands of Burmese pythons, which are native to Southeast Asia, are believed to be living in the Everglades, where they thrive in the warm, humid climate. While many were apparently released by their owners, others may have escaped from pet shops during Hurricane Andrew in 1992 and have been reproducing ever since.

Burmese pythons can grow to be 26 feet long and more than 200 pounds, and they have been known to swallow animals as large as alligators. They and other constrictor snakes kill their prey by coiling around it and suffocating it.

The National Park Service has counted 1,825 Burmese pythons that have been caught in and around since 2000. Among the largest so far was a 156-pound, 16.4-foot one captured earlier this month.

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 , 98.9 percent for , 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.

Although scientists cannot definitively say the pythons are killing off the mammals, the snakes are the prime suspect. The increase in pythons coincides with the mammals' decrease, and the decline appears to grow in magnitude with the size of the snakes' population in an area. A single disease appears unlikely to be the cause since several species were affected.

The report says the effect on the overall ecosystem is hard to predict. Declines among bobcats and foxes, which eat rabbits, could be linked to pythons' feasting on rabbits. On the flip side, declines among raccoons, which eat eggs, may help some turtles, crocodiles and birds.

Scientists point with concern to what happened in Guam, where the invasive brown tree snake has killed off birds, bats and lizards that pollinated trees and flowers and dispersed seeds. That has led to declines in native trees, fish-eating birds and certain plants.

In 2010, Florida banned private ownership of Burmese pythons. Earlier this month, U.S. Interior Secretary Ken Salazar announced a federal ban on the import of Burmese pythons and three other snakes.

Salazar said Monday that the study shows why such restrictions were needed.

"This study paints a stark picture of the real damage that Burmese pythons are causing to native wildlife and the Florida economy," he said.

Explore further: Half-tonne of smuggled ivory seized in Saudi

More information: “Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park,” by Michael E. Dorcas et al. PNAS.

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Telekinetic
3.7 / 5 (6) Jan 30, 2012
Here's Mitt's plan for the elderly.
dnatwork
4.3 / 5 (4) Jan 30, 2012
This could have been predicted decades ago, and probably was. But there was no regulation to prevent this tragedy because government is bad (and there was money to be made).
Callippo
1.7 / 5 (6) Jan 30, 2012
The pythons aren't the primary problem - it's source is in global warming, which opens the niche for predators, the population of which is limited to warm areas.
TheGhostofOtto1923
1 / 5 (1) Jan 30, 2012
"Pythons apparently wiping out Everglades mammals"

-Naw just the stupid fat and lazy ones. Because this is how natural selection works.
hyongx
5 / 5 (1) Jan 30, 2012
"My anaconda don't. want. none. unless you got. bun(nie)s. hon."
Shootist
5 / 5 (1) Jan 30, 2012
This could have been predicted decades ago, and probably was. But there was no regulation to prevent this tragedy because government is bad (and there was money to be made).


Yawn. Chuckles, if you make a government powerful enough to give you everything you want you'll have a government powerful enough to take everything you have. Better dog-eat-dog anarchy, than its opposite.

Offer $100 bounties on python skins. Give the teenage mutants, androids, vampires, werewolves and zombies, something to do. Miami, Ft. Lauderdale and Ft. Myers all have plenty of adult children with time on their hands.
tadchem
not rated yet Jan 31, 2012
The population estimate ("Tens of thousands of Burmese pythons") is hardly consistent with a few 'pets that were turned loose by their owners when they got too big'. It is *very* consistent with a breeding population arising from a number of males and females released in the same time and place, in an area free of predators and with abundant food. Ockham's Razor votes for the 'hurricane survivor' scenario.
dOlOb
not rated yet Jan 31, 2012
once the 'small mammals' are gone I guess that leaves your cats,dogs, and little kids! Oh my! Hmm! Die offs are wonderful! I love Darwin. Who wins, shoes or snakes? I suppose your little kid is just collateral damage for shoe makers.