Snake in the Grass. Larry Perez. Читать онлайн. Newlib. NEWLIB.NET

Автор: Larry Perez
Издательство: Ingram
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Жанр произведения: Биология
Год издания: 0
isbn: 9781561645749
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because it did not seemingly defy the natural order in the River of Grass. Still, it was of significance to the park. Before the encounter recorded in Taylor Slough, it appeared the only organism capable of purging Burmese pythons from the Everglades were people who, like those I encountered in the visitor center, came armed with Rubbermaid containers and questionable motives. Confirmation that at least one alligator had successfully taken its rightful throne as the apex predator in the Everglades was cause for some optimism. Perhaps there was hope that the natural system might self-regulate, that a biological means of control might be found to keep pythons numbers in check. Perhaps there was some reason to suspect the Everglades, having survived a century of unrelenting change, might also be capable of surmounting this latest plague. Unbeknownst to park staff, such guarded optimism was destined to last only four short months.

      2

      Michael Barron has flown helicopters over the vast horizons of Everglades National Park for years. During that time, he has piloted researchers to every remote corner of the backcountry, scoured the landscape in search of bird rookeries and alligator nests, and ferried countless firefighters to the front lines of sprawling conflagrations. And yet despite all he has seen in the wilds of south Florida, little could compare to what he encountered while hovering over the marsh one day in September of 2005.

      Flying high above the northern reaches of the park with a pair of researchers on board, Barron saw an unusually shaped figure below. Deciding to investigate, he set the floats beneath his craft gingerly into the inundated sawgrass prairie. Exiting the vehicle, he sloshed a short distance through hip-deep water to find a gruesome scene. There, floating amidst emergent vegetation and open water were the decapitated remains of a nearly 13-foot Burmese python. The animal was badly bloated, and protruding from its ruptured stomach were the tail and hind quarters of what appeared to be a large alligator. Barron surveyed the scene briefly, but didn’t stay long. “I started getting a little nervous about being up to my waist in the water,” he later recounted, “in an area where there’s twelve-foot pythons hanging around.” Barron managed to snap a few quick photos before returning to his airship for the journey home (Figure 4).

      The subsequent day, Barron piloted park biologist Skip Snow out to the area to examine the macabre curiosity he had found in the marsh. Upon landing, Snow set to work. Conducting a necropsy in the field, Snow determined the alligator (now in an advanced state of decay) to be over six feet in length. In the python’s intestines, he found large pieces of the alligator’s skin. Though the puzzling scene provided little to explain why the serpent perished, how its stomach ruptured, or how it lost its head, one thing seemed clear—at some point the python had managed to subdue and consume the monarch of the Everglades marsh.

      Media interest flared yet again as news of the discovery spread. Snow was interviewed extensively, and Barron’s crime scene photos were published around the world. Numerous national papers detailed the story, touting banner headlines reading “Clash of the Titans” and “Fatal Indigestion.” Internationally, the gory pictures of the eviscerated serpent were bandied about by the BBC, The Sydney Morning Herald, and The Daily Telegraph. And taking a cue from America’s Most Wanted, National Geographic aired an hour-long documentary that attempted to expose details behind the fatal encounter. Using sophisticated computer animations and laboratory experiments, the episode only added to the confusion by offering a new hypothesis that implicated a second alligator in the scuffle. Despite extensive investigation, the curious double homicide would forever remain steeped in mystery. But for many viewers and readers, the resulting coverage and publicity provided their first glimpse of the Florida Everglades—one far different than the idyllic picture-perfect sunset over an open expanse of sawgrass.

      In addition to providing new insight regarding the mutual relish with which alligators and pythons might consume one another, Barron’s gruesome discovery also provided an important new data point. The amazing alligator-eating python was one of the first of his ilk to be found in Shark Slough—the liquid heart of Everglades National Park. Not only were pythons now known to be capable of swallowing large alligators, but it was becoming increasingly apparent that they readily occupied the same watery haunts.

      In a coincidence that mirrored a bad publicity stunt, ABC premiered Invasion, a suspense series about aliens infiltrating the Florida Everglades, that same month. The show featured sets that barely resembled the Glades, starred impossibly attractive actors playing park rangers, and followed a storyline as thin as spider’s silk. In only a year, the show’s viewership went south, but in the true Everglades it seemed real invaders were headed farther north.

      _____

      Historically, the Burmese python (Python molurus bivittatus) has long proven difficult to categorize—so much so that successive generations of taxonomists have waffled about its proper classification. For the better part of a century, it has been defined as one of two closely related subspecies that occupy a large swath of south Asia and several associated islands. The Burmese python and Indian python (Python molurus) are so closely related, in fact, that some scientists continue to argue their true familial ties. Physical differences between the snakes are minute, and include slight, but fairly consistent, variations in color pattern and scalation. But it is the reproductive preferences of these subspecies in the wild that poses perhaps the greatest argument for elevation of each to specific rank. Though interbreeding yields healthy offspring in captivity, there is an apparent reluctance between subspecies to mate in the wild, despite overlaps in the range of each. The ambiguities in their life histories yield two camps of thought—“splitters” who opt to maintain their sub-specific distinction, and “lumpers” who regard both races as a single species.

      When viewed collectively, the species is a habitat generalist, capable of thriving in ecosystems spanning a variety of elevations—from sea level mangrove swamps to lower mountain forests sometimes as high as 3,000 feet. Its natural range extends to areas of both tropical and temperate climes—from semi-arid grasslands and deserts to wetlands of abundant rainfall. Regardless of where they are found, these pythons normally utilize the full gamut of natural features in an area, frequenting burrows, trees, rocky outcroppings, riparian zones, open water, and disturbed lands. In so doing, the snakes exercise their astonishing ability to swim, climb, and contort their bodies to meet the demands of the landscape. They are aided, of course, by tools forged over time through evolution: a supple skeleton, sinewy layers of muscle, and strong prehensile tails.

      The species can adapt surprisingly well to hostile environmental conditions. In the northernmost reaches of its range, for instance, pythons are able to endure harsh winters during three-to-four-month periods of hibernation. In areas of constant inundation, the heavy-bodied pythons prove semi-aquatic in nature, comfortably spending significant time maneuvering their bulk both above and below the surface of the water. Pythons have also been known to persist in both disturbed and human environments, though it has been noted by some that they fare best amidst more natural habitats. And though it is also not their preferred haunt, pythons can even tolerate exposure to salt water for short periods of time while they comfortably navigate coastal waters.

      Indian pythons and Burmese pythons occupy fairly distinct ranges south of the Himalayas. The former occupies nearly the entire South Asian subcontinent, where it is found primarily across large swaths of Pakistan, India, Nepal, and Sri Lanka. By contrast, Burmese pythons are generally encountered further east along a continuous range from northeastern India to southern China, with smaller, isolated populations also persisting in Nepal and on the islands of Java, Bali, Sumbawa, and Sulawesi. The details of natural distribution and biology are only partly known—informed by a limited collection of observations and studies from the field. But over the years, the study of captive animals has helped shed light upon the life histories of many snakes—particularly the Burmese python.

      Hatching from the egg at only twenty inches, Burmese pythons experience one of the fastest growth rates known among snakes. During their first year of life, some can grow half a foot per month—particularly if fueled by regular feedings. Pythons reach sexual maturity sometime between reaching five and eight feet in length, a goal which can take as few as two to three years to achieve. The pace of growth slows gradually with age, but nonetheless permits both sexes to attain double-digit lengths. The females, however,