Species and Sprawl: A Road Runs Through It
Species and Sprawl: Wood Turtles
F15 has no tail, only three legs, and a transmitter with a 30 cm long antenna epoxied to her back. Considering F15 is a turtle—and one who must regularly cross a well-trafficked country road to find food and lay her eggs—missing a foot sounds like a cruel twist of fate.
But F15’s battle scars are par for the course. After all, at possibly 50 or 60 years old (in both people and turtle years), she’s been through her share of raccoon sneak attacks and near-misses with plough blades in her habitat—the streams, hayfields, woodlands, and backyards of the rapidly suburbanizing, formerly agricultural Connecticut River valley.
Biologist Mike Jones holds F15, a female wood turtle he tracks with radio telemetry. A coiled antenna circles her shell, affixed with white dental acrylic.
Mike Jones, a biology graduate student at the University of Massachusetts at Amherst, has been following F15 and 52 of her shelled compatriots in the most comprehensive study yet of the habitat use and range of Clemmys insculpta, or wood turtle. The species is of conservation concern in Massachusetts and most of the 16 U.S. states and 4 Canadian provinces it calls home. For the last nine months, Mike has been tracking F15’s whereabouts twice a week via radio transmitter. And he can tell you, unequivocally, that she has not been flattened by an SUV. Yet.
“The new homes, businesses, and malls that we associate with urban sprawl are connected via roads,” says Paul Sievert, a U.S. Geological Survey ecologist and lead researcher on the wood turtle study. “This fragments the habitat into smaller pieces and increases the traffic rate on the roads currently in existence. There’s not enough time for a turtle to cross the road.”
The research is intended to provide a clearer picture of how much and what kind of space wood turtles need to survive, and to determine whether existing populations can surmount pressures from sprawl and persist in perpetuity. Jones’s and Sievert’s work will eventually guide a Division of Fisheries and Wildlife conservation plan to protect wood turtle habitat in Massachusetts, a state with some of the tightest environmental laws in the country.
Keep on Truckin’
In less than a hundred years, wood turtles have dwindled from common to fairly scarce in their historic range, which spans the Great Lakes region, New England, and southern Canada. “In New England in the 1800’s, people recorded that they went out with their horse and buggy, and in an afternoon picked up a hundred wood turtles,” says Sievert. “Fast-forward to today. If you find a wood turtle at all, it’s usually a road-killed wood turtle.”
Wood turtles spend most of their days swimming in, basking in, and exploring one cold, brisk stream for their entire lives. The study area in this case is the headwaters of one of the Connecticut River’s 38 main tributaries. Still, the reptiles leave the river regularly to forage for amphibian eggs at vernal, or temporary, pools in adjacent woodlands or to lay eggs in warm, sandy upland sites.
To trail the exact moves of each turtle, Jones uses dental acrylic to affix a transmitter and coiled antenna onto the shell. He programs a handheld receiver to pick up each turtle’s personal signal. Suited in fisherman’s waders and paddling a canoe, Jones relocates each turtle about twice a week during the spring, summer, and fall, noting its GPS location, surrounding habitat, and behavior. “Eventually we’ll be able to measure each turtle's habitat selection on a very large scale,” he says.
It's Not Easy Being Green. Er, Brown and Orange.
During their meanderings, turtles are almost sure to encounter a road, or two, or three. That’s because humans like to build roads parallel to river edges, as construction is much easier along flat riverbeds. Turtles often travel perpendicular to rivers, which usually entails dodging tires.
