American Heritage - Tracking North America's Largest Snake

National Wildlife, Oct-Nov, 2001 by Don Stap

Stephanie is missing. There has been no sign of her for three weeks. Biologist Rebecca Smith, who has been keeping an eye on Stephanie for the past year, says that there's no point in looking for her now. It is cool and overcast on this December day in central Florida, so Stephanie is probably holed up somewhere, trying to stay warm. Stephanie, after all, is cold-blooded. She is, in fact, one of 74 eastern indigo snakes that Smith has outfitted with radio transmitters during the past three years while trying to answer basic questions about the life of North America's largest snakes.

The elusive eastern indigo snake--a subspecies of the indigo snake, which ranges from Georgia, Florida and Texas through South America--has been federally protected as a threatened species since 1978. But because so little is known about the snake, not much is being done to protect it. "There have been very few studies of any kind and hardly any data published," says Smith. "We don't even know how often females reproduce or how long indigos live in the wild." As long as such questions remain unanswered, it will be hard to halt the population decline that appears to have eliminated the snake from most of its former range.

Eastern indigo snakes, once found from Mississippi to South Carolina and south through the Florida peninsula, today occur only in southern Georgia and Florida. But even in most of these areas the snake is becoming increasingly rare. Habitat loss and fatal encounters with cars have contributed significantly to the population decline. There are other reasons for their dwindling numbers: Some people kill indigo snakes simply because they are snakes, while others--poachers--collect them for the pet trade.

An adult eastern indigo is typically six or more feet long. (The record is eight feet, seven inches.) The snake is entirely iridescent black except for a pale wash of coral red along the throat and upper belly. Nonpoisonous, it is still a powerful predator, pinning down its victim to subdue and swallow it alive. The indigo makes a meal of frogs, turtles, lizards, fish, birds, small mammals and occasionally even rattlesnakes. But it is remarkably docile in the presence of humans.

Its affinity for people might explain why Smith and her colleague in the study, Mike Legare, name the snakes they capture. Smith says it's simply easier to use names than numbers to identify them.

This afternoon, with Stephanie nowhere to be found, Smith heads off to look for Odie. Legare had located this snake earlier during a morning aerial survey. Like Stephanie, Odie needs to have his transmitter replaced. The batteries only last a year.

Smith meets Legare on the outskirts of an industrial park just outside the Kennedy Space Center, where both wildlife biologists work as private environmental consultants to NASA. Legare leads the way down a sandy path into woods dominated by palmettos, wax myrtles, scrub oaks and longleaf pines. They have to bull their way through the dense undergrowth of palmettos but stop repeatedly while Legare moves the antenna of his radio receiver in the air, listening to the beeping signal that is coming from Odie's transmitter.

Within 20 minutes Legare locates Odie beneath the ground at the base of a palm tree. Although indigos may roam widely by day, actively searching for prey, they remain in burrows when the weather is cool. Smith and Legare know this all too well: They've brought a shovel. The idea is to dig a hole into the burrow, spot the reptile and grab it with a snake stick. It's a good idea. But after an hour and a half of trying to get past the palm tree's dense mass of roots, the researchers have created only two small holes. And there's been no sign at all of Odie.

Aware that daylight will run out soon, Legare gets on his knees to dig with his hands, ripping up dirt and roots like a dog. Suddenly, he stops. "I see him. Don't anyone move," he says. Moments later Legare has a handful of snake. He pulls Odie out of the burrow and hands him to Smith. The big snake seems unperturbed despite this rude interruption of his nap. And that is a good thing because Smith has to carry him back to the car in her arms; no one has remembered to bring a snake bag along on the outing. Smith holds Odie over her head and struggles through the thick palmettos. Odie, curled around her arms, calmly surveys the woods from his new vantage point.

When a new transmitter is implanted in Odie later this afternoon, Smith and Legare will be able to follow him for another year thanks to the funding and efforts of a private wildlife trust, the U.S. Fish and Wildlife Service and NASA. But Smith is concerned that this support will only provide enough time and resources to track the snakes. "We also need time to analyze the data," Smith says.

She points to preliminary findings that are already cause for grave concern about the indigo's life in crowded central Florida. "We were surprised with how many snakes we found in residential areas," Smith says. "The mortality rate for snakes in those areas is high."