Snakes on a Glade

Florida has been wrestling with its python problem for years. Thanks to the tropical temps in south Florida the Everglades National Park has become a dumping ground for unwanted reptiles, particularly the non-native Burmese python. Wildlife officials have been battling the snakes for about twenty years.

They presume that parents of kids who outgrew their pets and the pets who outgrew their owners freed the snakes in the swamp. Some also believe that the wild python population began to grow after Hurricane Andrew destroyed pet stores selling the exotic snakes in 1992.

Fast-forward 20 years where this month, Department of the Interior Secretary Ken Salazar announced a federal ban on four imported snakes including the Burmese python which has a choke hold on southern Florida. U.S. Fish & Wildlife officials believe there are tens of thousands of snakes lurking in the Everglades.

On a regular basis, giant snakes are turn up in backyard swimming pools, terrorizing neighborhoods. And in November game officials found a 16-foot python that had swallowed a 76-pound deer. Burmese pythons can grow to 26 feet and weigh well over 200 pounds. And unlike in its home in southeast Asia, there are no known predators in Florida that keep the snake population in check.

A study published Monday in the Proceedings of the National Academy of Sciences has found that sightings of medium-sized animals like racoons, oppossums, rabbits, foxes, deer and bobcats are down dramatically — as much as 99 percent — in some parts of the Everglades where these snakes are most commonly found.

There is no way to tell for sure that the Burmese python is solely responsible for the drastic decline in medium-sized mammals. But scientists suspect it is. They are concerned that the invasive species will disrupt the food chain in the Everglades and upset the delicate ecosystem balance.

J.D. Wilson, a Virginia Tech research biologist and co-author on the study says, “The effects of declining mammal populations on the overall Everglades ecosystem, which extends well beyond the National Park boundaries, are likely profound.”

Between 2003 and 2011 researchers drove 39,000 miles of Everglades area roads, counting wildlife. Since 2000 the National Park Service has counted 1,825 Burmese pythons in and around the national park. The largest, 16.4-foot snake weighed 156 pounds and was captured earlier this month.

Michael Dorcas, a biologist from Davidson College in North Carolina and the lead author of the study says, “The magnitude of these declines underscores the apparent incredible density of pythons in Everglades National Park.”

Here are the significant declines in medium-sized mammal sightings in the Florida Everglades.

Raccoons — down 99.3 percent
Oppossums — down 98.9 percent
White-tail deer — down 94.1 percent
Bobcats — down 87.5 percent
Rabbits — down 100 percent (no sightings)
Foxes — down 100 percent (no sightings)

The research also found slight increases in coyotes, Florida panthers, rodents and other mammals. But because those sightings were so rare they discounted them altogether.

Secretary Salazar says, “This study paints a stark picture of the real damage that Burmese pythons are causing to native wildlife and the Florida economy.”

The state of Florida banned the private ownership of Burmese pythons in 2010. Now the federal government announced new rules on January 17 that will ban the importation and interstate transport of Burmese pythons, yellow anacondas and three other invasive constrictors sold in the pet trade. All have been found roaming Everglades National Park.

Some believe the federal mandate goes a little too far. Practically, the snakes can only survive outside in a few parts of the country, including south Florida and Louisiana. The rest of the nation is just to cold for the snakes to take hold. Snake breeders and experts who use the mighty constrictors to educate people about reptiles say the overall ban could lead to a burgeoning black market for Burmese pythons and could hurt legitimate businesses in the process.

With some estimates of the Everglades invasive snake population approaching 30,000 research turns to understanding and limiting the spread of the invasive snake species.

Burmese pythons need freshwater to survive. But a team of biologists with the U.S. Geological Survey led by Kristen Hart in its Davie, Florida lab showed that the snakes can drink in their much-needed moisture through the tissue of animals they swallow. The team also ran experiments trying to understand the snakes relationship to water.

The team’s experiments suggest that newborn pythons can’t survive more than two months with only access to saltwater. But a pair of hatchlings survived over 200 days with access to only brackish (mix of fresh and saltwater) water. And a yearling snake with access to only saltwater survived 7 months. New research in the upcoming Journal of the Experimental Marine Biology and Ecology suggests that these super-swimming snakes could head for the sea and migrate long distances.

Already, Burmese pythons have already been found eating endangered wood rats on Key Largo, off the mainland Florida coast. The first snake was discovered alive in 2007 when two researchers studying federally endangered Key Largo woodrats were checking on the status of a male woodrat wearing a radio transmitter that had suddenly moved more than a mile from its original documented habitat.

The signal led the researchers — a University of St. Andrews graduate student Joanne Potts and a volunteer assistant — to a eight-foot Burmese python sunning itself.

The contents of the captured snake’s stomach included not only the collared woodrat but a second woodrat as well.

Jack Hanna, the director emeritus at the Columbus Zoo believes the Florida python problem is a state issue not a federal one. He is concerned that the far-reaching ban on exotic constrictors will choke commerce. He tells CBS This Morning the new ban might effect the 220 breeding programs at the nation’s zoos as well as hurt snake breeders.

He says, “There are reputable breeders in Florida and we can’t put these guys out of business because they help and there is a logical role with a lot of our breeding programs [at zoos].