WHERE HAVE ALL THE PYTHONS GONE?
by Whit Gibbons
November 6, 2011
"Invasive Pythons in the United States: Ecology of an Introduced Predator" might be the title of a great new horror film instead of the well-researched, professional yet entertaining book that it is. Written by Michael E. Dorcas and John D. Willson (2011, University of Georgia Press, Athens; $24.95) "Invasive Pythons" sets the record straight about the thousands of Burmese pythons introduced from Asia that now thrive in Florida. These snakes can be longer than two pickup trucks parked end to end and weigh more than an NFL linebacker. Not a pet snake you'd want to drape around your neck.
Nonetheless, released or escaped animals from the pet snake trade are almost certainly the origin of these enormous nuisance predators that now slither through southern Florida. What do pythons eat? In their native lands from India to China they have been documented to eat mammals as large as jackals, monkeys, antelope, and even a leopard. Accounts of humans becoming python prey are rare but unfortunately true. In their new home in the Everglades National Park and surrounding areas, pythons have found plenty of native mammals and birds to consume, some in disturbingly high numbers. Alligators as well as virtually all warm-blooded wildlife are apparently fair game. A valid concern is that pythons in Florida will eventually consume pets such as dogs and cats. Records already exist of their eating domestic chickens, geese, and turkeys.
The book's focus is on Burmese pythons, but the authors also discuss the potential risk of other species of pythons and boas becoming established in southern Florida. Included are African rock pythons and green anacondas. Both reach lengths exceeding 25 feet and have been found in the Everglades.
A feature that will captivate many readers--from youngsters enthralled with snakes to naturalists of any ilk to professional herpetologists--are the 188 outstanding high-resolution color photographs. To say that some are dramatic would be an understatement. The picture of the authors and two colleagues holding a 16-foot female Burmese python captured at night in Everglades National Park is enough to make anyone realize that studying these reptiles is an adventure. Other Everglades photos include a large python coiled around an adult great blue heron that's about to become lunch and a giant alligator eating a large python. A photo of a female python coiled around her eggs illustrates a more maternalistic trait: the mother staying with the clutch until they hatch, thus incubating them by raising her own body temperature and protecting them from predators.
Barring yet unknown population controls for these invasive predators, which can hatch more than 40 young from a clutch, Burmese pythons can now be considered part of the naturalized fauna of Florida. Are they likely to expand their geographic range into Georgia, Alabama, the Carolinas, and beyond? According to the authors, expanding their range outside of Florida will take quite awhile. How far north they can go is heavily debated by scientists and commercial python breeders. In their native range in Asia, they extend into cool areas in central China and to the foothills of the Himalayas in India and Nepal. But new population centers in the United States could arise in another way. Without originating from the solidly established Florida population, a released female python that has outgrown its owner's cage might ultimately be the source of a new population in California, Louisiana, or other temperate regions in southern portions of the country. On the other hand, large pythons have been found in recent months as far up peninsular Florida as Lake Okeechobee, almost a hundred miles north of the heavy concentrations in the Everglades.
Hollywood screenplay writers and science fiction authors hold the franchise on horror tales of Earth being invaded by scary monsters. The gigantic, stealthy, and potentially man-eating predator described in "Invasive Pythons" is scarier than any of those imaginary creatures because it's real. Whether for its scientific facts, fascinating natural history information, entertainment value, or striking photography the book by Mike Dorcas and J. D. Willson should appeal to a wide audience.
If you have an environmental question or comment, email
