By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM and Maps.com*
Florida’s famous Everglades National Park is experiencing one of its greatest ecological threats. Burmese pythons, which are native to Southeast Asia, are devastating the native wildlife of the Everglades. How the pythons reached South Florida and became a reproducing population of thousands that is decimating the local animals and what is being done to control the ecological damage are news items of national interest.
Recently, the National Park Service- and the Florida Fish and Wildlife Commission-supported bounty system to help control feral pythons in the Everglades was initiated. The first month-long hunt involving 1,500 registered hunters ended Feb. 10, 2013, and killed only about 50 pythons, but the hunt was labeled a success. More broadly-supported hunts will likely follow, as more is learned from the recent experiences.
Burmese pythons are members of the constrictor family, different varieties of which are found throughout much of the world’s tropics. Many of these varieties were imported into the U.S. as pets during the past 30 years. At ages less than two years old, Burmese pythons are relatively docile, but they grow rapidly in captivity, particularly when fed mice and rats regularly. In their native habitats, their carnivorous diets are more sporadic, depending on the availability of other species ranging from snakes to mammals.
Burmese pythons can live up to 30 years and grow to more than 20 feet (7 m.) in length and to a weight of more than 200 pounds (91 k.). At maturity, they can consume animals as large as full-grown deer and even mature alligators. Many python owners find the cost of feeding and housing full-grown pythons overwhelming, not to speak of the dangers they pose to pets and even children. In desperation, owners have released python “pets” into the Everglades and others simply escaped confinement during storms and other emergency events.
Pythons are well camouflaged, secretive and nocturnal, moving almost silently on the ground among the vegetation and in trees. They are fast underwater swimmers and can remain submerged for 30 minutes. The only geographic limits to their survival are: 1) several weeks of near or below freezing temperatures, 2) desert conditions, and 3) lack of accessible food sources. The Everglades represents an optimal habitat for their survival, but no one can predict the future geographical spread of the feral python.
By early 2012,, authorities had removed, captured or killed more than 1,800 pythons in the Everglades. There are no reliable estimates of the total number of the established invasive population. Female pythons can produce more than 30 eggs in a breeding season.
The damage to the native Everglades mammal populations is evident in the reported reductions of sightings of raccoons, rabbits, opossums, foxes, bobcats and whitetail deer by 90 to 98 percent in some areas.
Stomach contents of captured or killed pythons have included an eight-foot alligator, an adult whitetail deer and numerous species of animals and birds, some on threatened and endangered lists. The pythons are larger than native snakes and less susceptible to predators. A large python can exert enough pressure on its prey’s body to cut off respiration, even that of an alligator. One child’s death by a pet python in Florida has been documented, although none has occurred in the wild at this point.
A film crew with the Florida Wildlife Corridor Expedition recently crossed the Everglades in kayaks from south to north. This was part of the expedition’s 100-day, 1,000-mile (1,609 km) trek to call attention to Florida’s wildlife and wildlife corridors. (www.floridawildlifecorridor.org). According to their film producer, Elam Stoltzfus, the team did not see any pythons and few small animals at all in the first 30 days. Whether this was an anomaly associated with the season or some other happenstance is unknown. It is clear in speaking with the Everglades National Park information officer, Linda Friar, however, that pythons are very hard to see due to their natural camouflage pattern.
Efforts to capture feral pythons are usually successful when they are seen, but randomly searching for them is very difficult. Biologists have been successful in capturing and implanting radio receivers on a few in attempts to follow them in the Everglades. It appears, however, that pythons are not very communal except during mating and usually are widely dispersed, perhaps because of competition for food.
Occasionally, pythons venture into inhabited areas. They have been found in backyard swimming pools, where they could be a danger to pets and children. Generally, it requires a team of several adults to capture large pythons to keep the snake from wrapping its constrictor body around a single individual. One person would find a 12-foot (3.7-m) python impossible to handle alone.
The National Park Service has begun an educational program called “Don’t Let It Loose,” referring to the intentional release of nonnative pets into the Everglades ecosystem. Alana Edwards, an environmental education specialist at Florida Atlantic University, explains to children how exotic animals can be destructive to the natural ecology where they have no enemies.
Now all eyes are on the Burmese pythons, their potential damage to the Everglades’ ecology and whether they can be contained geographically within the Everglades. The small number of pythons eliminated from the Everglades in the recent hunt still indicates that it may be a successful method o f controlling the python population, as more hunts are scheduled in the future.
And that is Geography in the News.
Co-authors are Neal Lineback, Appalachian State University Professor Emeritus of Geography, and Geographer Mandy Lineback Gritzner. University News Director Jane Nicholson serves as technical editor.
Sources: http://www.mcclatchydc.com/2012/01/13/135839/new-rule-would-ban-imports-of.html; http://www.bradenton.com/2011/12/27/3750284/13-foot-burmese-python-found-in.html; http://www.huffingtonpost.com/2011/10/31/florida-16-foot-python-deer-photos-pictures_n_1068228.html#s445129; and http://edis.ifas.ufl.edu/uw286; http://www.rexano.org/pythons.htm
*Nearly 900 of the 1200, full-length weekly Geography in the News articles (with Spanish translations) are available in the K-12 online education resource Maps101.com, including maps and other supporting materials and critical thinking questions.