Snake in the Grass. Larry Perez

reaching the length of a stretch limousine and tipping the scales at several hundred pounds.

      To accommodate such growth, Burmese pythons readily consume any meal that satisfies their hunger. Diet is generally restricted to warm-blooded terrestrial animals, leaving a wide variety of potential prey on the menu. The python’s prowess at capturing, constricting, and consuming large prey has made it a staple of wildlife documentaries. But in addition to mind-boggling meals of leopards, deer, and antelope, the python feeds upon a much greater spectrum of both large and small fauna that includes wading birds, rodents, porcupines, bats, and domestic livestock. Though mammalian and avian prey is clearly preferred, the snakes are ultimately opportunistic in their feeding—known to consume even the occasional lizard, frog, or toad.

      Cryptic coloration and a predilection for slow, deliberate movements provide an effective strategy for pursuing a meal. Burmese pythons are ambush predators that patiently lie in wait for their prey to advance. Engaged in attentive repose, pythons silently gather data using a sophisticated array of serpentine gadgetry—a sensitive inner ear transmits minute vibrations on the ground, a forked tongue processes molecules of odor captured from the air, and a full network of facial pits detects slight changes in temperature nearby. It is unclear whether it is motion, sight, or smell (or some combination thereof) that triggers the snake to feed.

      Whatever the cue, it commands near-instantaneous strikes—widening jaws bearing rows of wretchedly recurved teeth capable of ensnaring an unsuspecting passerby. This bite, though no doubt painfully alarming, is nonfatal. Lacking venom, Burmese pythons must subdue their meal by sheer force. Using its mouthful of sharp barbs to hold fast the unfortunate captive, the snake throws coil upon coil around the body of its victim, exerting ever-increasing amounts of intense pressure. So strong is this fatal embrace it can at once squeeze breath from the lungs and render the heart inert. After some time, when movement is no longer detected, the large constrictor slowly relaxes its vicelike grip to finally indulge its appetite.

      Though people are fascinated by the size, girth, and predatory instincts of the Burmese python, it is in other respects a fascinating biological creature of inspired design. Their seamless camouflage and capacity for stillness are well-developed traits that serve them not only in ambushing prey, but also constitute an effective strategy for self-preservation. A strong, prehensile tail allows them to hoist, suspend, and cantilever their bulk into trees high above the ground. The series of thermal pits that accents their lips allows for continued monitoring of their surroundings—enabling the detection of even minute differences in temperature nearby. And like other primitive snakes, Burmese pythons boast conspicuous pelvic spurs, which aid them in the requisite tickling and grasping that accompany courtship.

      The reproductive habits of several python species are well documented, partly thanks to observations in the field, and partly due to the frequency and ease with which they are bred in captivity. Burmese pythons show great variability in the number of eggs they lay. While most will typically produce several dozen eggs at a time, both single-digit clutches and those in excess of 100 have also been reported. In captivity, females can be induced to lay a clutch every year, but in the wild they are more likely to produce a clutch every two to three years. During the time necessary for gestation and incubation a female python will often forgo all food—a prolonged period of four to six months during which she grows increasingly lean. Once her eggs are laid, a female python will swaddle her unhatched progeny in a protective stack of body coils. Should the ambient air begin to cool around them, the vigilant mother will begin to repeatedly contract the muscles in her lengthy body in a rhythmic fashion. As temperatures drop, these full-body spasms will grow ever more rapid and her coils will grow taller and tighter in a bid to generate heat for her unborn young. It is a display of maternal dedication rarely found among other reptiles, and a feat relatively unknown among cold-blooded animals—for a short span of time, she is actually capable of regulating her own body temperature for the benefit of her offspring.

      Many facets of the life history of the Burmese python remain poorly understood. The extent of their distribution in certain portions of their native range still remains uncertain and in need of further study. The social workings of these large creatures remain somewhat shrouded in mystery, though observations of captive pythons provides some evidence to suggest a clear hierarchy may exist—particularly with regards to courtship. Both the density of Burmese python populations and the relative impact of disease and parasites on them still require further investigation. Even the full reproductive mechanisms of this species remain in question—some evidence exists that females may be capable of producing clutches of genetically identical young asexually through a process known as parthenogenesis.

      The longevity of Burmese pythons in the wild also remains a great unknown. What little can be speculated about their span of life can only be gleaned through records of captives, some of which suggest exceptional animals can reach ages in excess of thirty years. In fact, one of the oldest known captive Burmese pythons died in 2009 at the ripe old age of 43. At the time of her passing, Julius Squeezer measured 18 feet long and weighed 220 pounds. Marty Bone, an avid snake enthusiast, had shared his home with Julius for 35 years, having acquired her as a full-grown adult. Bone attributed her exceptional longevity to both the freedom she enjoyed and the affection he showered upon her. Bone allowed Julius unfettered access to his home and, over time, she reportedly learned how to open doors merely by wrapping her body around doorknobs. Marty modified furniture in his home to better accommodate Julius, and even allowed her to curl up with him in bed. “At night she’d lay her head on me,” Bone recalled. “She was my bedmate, housemate . . . she was special to me.”

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      Burmese pythons are strictly an Old World species. Still, much of our current knowledge about their natural history has come squarely from our experiences with them in the Western Hemisphere. Zoos, dealers, and private collectors have provided detailed information on their reproductive habits. University studies have furnished information on social behavior, feeding response, energy efficiency, and the effects of visual deprivation. Even the sad passing of Julius Squeezer in a private Utah home provided an important bit of data about potential species longevity.

      The establishment of Burmese pythons in south Florida provided a simultaneous need, and opportunity, for further study and data collection. By 2006 it seemed evident that the python population in south Florida was growing larger. Just a few years prior, park employees were removing only two or three of them from the area annually (Figure 5). But beginning in 2002 the yearly figures began to make surprising jumps—staff removed 14 individuals in that year alone. The following year they removed 23 more. In 2004, the count jumped yet again to 70, then to 94 the following year. The park seemed poised to hit triple digits by 2006—a sobering milestone considering it only reflected those snakes that were captured and removed. The annual tallies didn’t include the many animals reported that subsequently got away. Nor did they reflect those that remained altogether unseen.

      Increased awareness of the issue, the hiring of additional staff, a growing proficiency for capture, and a more concerted communications effort were all no doubt complicit in yielding higher rates of removal with every passing year. The clear statistical trend, however, was still unsettling. Evidence continued to mount suggesting the snakes were freely breeding in the wild. Park staff had thus far found pythons of various size classes throughout the Everglades, including juveniles. Newborn pythons had been recovered, some still bearing the ephemeral umbilical scars where their newly shed yolk sacs were once tethered. And several gravid females had been recovered—their innards packed to the walls with fertile eggs (Figure 6). Though the evidence of breeding was certainly compelling, it was not technically conclusive. Scientists had not yet happened upon the necessary “smoking gun”—neither copulation nor a nest site had been documented in the wilds of south Florida. To do so, scientists would need to learn as much as possible about the habits of this Old World serpent in its New World haunts.

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      Exactly who is to blame for the introduction of Burmese pythons into the Florida Everglades is a topic of much speculation, interest, and heated debate. Those who found it difficult to fathom keeping large constrictors as personal pets were quick to point their fingers at those that actually did. After all, history had already shown a loose correlation between the increasing popularity of reptile ownership and the