Rehabilitating Rattlers’ Bad Rep

By James Schultz

Coiled menacingly in the center of the human imagination, the rattlesnake is perhaps the most feared of all living reptiles. Most consider it a cold, relentless assassin that will strike without regard or provocation, delivering virtually instant death. Protection from human predation is the last thing that these venomous creatures need.

Not so, contends herpetologist Alan Savitzky, an Old Dominion associate professor of biology. It’s a myth that rattlesnakes are relentless killing machines. Rattlers are neither pernicious nor particularly aggressive, Savitzky attests, and avoid humans whenever possible. They are slow to bite, if they bite at all, relying on their skin’s natural camouflage to conceal themselves from potential predators and their rattles to warn away more aggressive intruders. Many more people die each year from simple household accidents — falling out of bed, walking across a slippery floor or stumbling on stairs — than have been killed by rattlesnakes in all of the 20th century.

In reality, rattlesnakes’ ugly reputation is undeserved, Savitzky believes, having less to do with true threat than fear and demonization in culture and myth. Treating snakes as an evil to be eradicated poses a much greater danger because it affects the healthy interdependence of creatures large and small. As snakes go, so goes the ecosystem. Not to mention that, by law in the commonwealth of Virginia, killing a canebrake rattler is illegal.

“Snakes are part of the natural diversity of our world. They are as worthy of protection as any other animal or plant,” Savitzky asserts. “Because they’re a top predator, they maintain an ecological balance. In a more basic sense, because rattlesnakes need a large area in which to live and move, they are a gauge of the health and expansiveness of our forests and how well or poorly we’re protecting them.”

Since 1992, Savitzky has been involved in scientific investigations to chart the movements, habits and life cycle of the canebrake rattlesnake, the only rattler known to inhabit southeastern Virginia. His rattlesnake research began in the 700-acre Northwest River Park in the Hampton Roads city of Chesapeake and continued until 1995. A year later, the U.S. Navy agreed to underwrite Savitzky’s snake studies within the confines of Naval Security Group Activity Northwest, a 3,000-acre radio-receiving facility also located in Chesapeake and adjacent to the North Carolina border. Savitzky has received funding from the Navy to continue his research through the second quarter of 2002.

“We’re dealing with an animal with an estimated lifespan of two to three decades,” Savitzky says. “We know more but not enough. We understand something about the canebrake’s preferred habitats and how they use the open habitat available to them. But the movement over time, year to year, season to season and what governs those differences — we’re a long way from understanding that.”

Habits Revealed

A subspecies of the timber rattlesnake, Crotalus horridus, the canebrake is a large, heavy-bodied snake with black, chevron-shaped markings on a dark yellow, gray or tan skin and an orange or rust-brown stripe down the middle of the back. The canebrake’s head is wide, with a deep pit on each side between the eye and nostril, a brown or yellow stripe behind the eye, a black tail and khaki-colored rattle.

A mature canebrake generally reaches a length of four-plus feet, with a maximum known length in Virginia of 5 feet 7 inches. Males tend to be slightly larger than females. Young are usually born no longer than 12 inches.

Historically widespread throughout forests of eastern North America, the canebrake is dwindling in numbers, with a range fragmented by widespread human development of formerly forested land. To find out how snakes move within their shrinking range — and, more specifically, within the Chesapeake naval facility and surrounding environs — Savitzky installs small radio transmitters in the canebrakes’ body cavities. At the end of the most current season, 15 rattlers were slated to be so outfitted (in all, 30 snakes have been telemetered over the past five years). To pinpoint the implanted snakes’ movements, full-time research associate Chris Petersen scours the Navy base’s thickly wooded acreage using a hand-held radio receiver and, on occasion, locator information supplied by an orbiting network of global-positioning satellites.

“For an animal that moves on its belly, the distance it can travel is impressive,” Petersen says. “[Snake tracking] is a very physical job. You walk a lot and hack away at undergrowth with a machete. It can get very hot and very buggy. But it’s a lot of fun. What keeps me going is my curiosity. Every year we go out and find new information that’s useful in helping to conserve the animal.”

Aided by volunteers and members of the Student Conservation Association on summer loan to the Navy, Petersen has created a series of canebrake-activity maps, using a geographical information system (GIS) to overlay observations and radiotelemetry on digitized aerial photographs of the study area. With a few keystrokes Petersen and Savitzky are able to call up data archived on the University computer system to examine serpent behavior over many seasons.

The result is an enhanced view of canebrake activity superimposed on detailed views of woodlands and countryside. The researchers have found that the rattlers prefer to feed in either deep forests or along the edges of clearings and take advantage of the full sunlight available in fields and meadows to bask prior to skin shedding. Because sexually receptive females generally copulate after a midsummer shedding event, and because such females are trailed by males, the clearings may figure prominently in rattlesnake movement. Savitzky suspects that variation in squirrel populations may be responsible for establishing the snakes’ reproductive intervals.

In their search for food and during mating, the snakes range far and wide. While males tend to move farther during the active season than females, pregnant females travel substantial distance in the spring from hibernation sites to places of gestation and birthing. By contrast, in midsummer, pregnant females move very little compared to non-pregnant females.

An Uncertain Future

Although intentional killing and highway fatalities claim the lives of many canebrakes, Savitzky believes the primary threat is loss of forest habitat. Although habitat was restricted in the past by the clearing and draining of moist forests for agriculture, recent loss results primarily from suburban development. Because the snake requires both wetlands and forested uplands, extensive clearing of forests poses the primary threat to its survival.

“The real burning question for us is what is the optimal habitat for these animals,” Savitzky says. “If this were a pre-Western, pre-European-settlement landscape, where would they occur most abundantly? Are they surviving in a sub-optimal habitat, because that’s the only one available to them? Or are they in an optimal habitat, one that just happens to have been developed by humans?”

In southeast Virginia, between the York and James rivers, in an area known to locals as the Peninsula, the situation is critical. Savitzky believes that within 10 years the canebrake could be extinct there. Only a few individuals are known to still inhabit the Peninsula’s extreme southern reaches and Savitzky doubts there will be enough habitat remaining in which the snakes can mate, live and thrive.

Working with the Navy, Savitzky and Petersen have established a rattlesnake display and information center at the Chesapeake naval facility. The effort is part of what Savitzky hopes will eventually be a larger, proactive program of public education in southeastern Virginia to inform citizens of the biological and historical significance of the rattlesnake, its current status, and actions that can be taken to promote rattlesnake conservation. Carefully supervised public observation of telemetered snakes at a secure site may one day be possible, as a means of promoting public appreciation of the snakes under natural conditions and to bolster the rattlers’ role in ecotourism.

Given the rattlesnakes’ poor reputation, rehabilitating their image could be a lengthy process. But Savitzky is willing to stay the course. Not too long ago, he says, many detested hawks and wolves. With time, and increasing public knowledge and awareness, snakes should benefit from a rejuvenated appreciation of their ecological role.

“For these populations to flourish, they need high ground to survive,” Savitzky says. “I’m guardedly pessimistic, even though we have the capacity to turn around the situation. If society so chooses, as we learn more about the animals, their movements and their requirements, we’ll ultimately be able to manage lands for their protection.”