Blanding’s Turtles Trek for Life

By Don Parker and Lauren Murrow

In a landscape of roads and hungry raccoons, how do we save a ten-inch turtle bent on travel? The ultimate answer will be to save enough habitat — but a “head start” may buy some time.

Dan Thompson gets a certain feeling just before Blanding’s turtles head for higher ground to lay eggs. Most years, his intuition, guided by research and experience, is off by only a day or two. “I go out, and all the turtles are in place,” he says. “But the next night, every one is out of the marsh.”

Thompson, an animal ecologist for the Forest Preserve District of DuPage County, just finished another spring season of Head Start, part of the district’s program to sustain the state-threatened Blanding’s turtle, Emydoidea blandingii. Known for its gentle demeanor, bright yellow throat, and permanent “grin,” the Blanding’s is a native reptile whose range centers around the Great Lakes. “Every spring, we round up females and x-ray them for eggs,” says Thompson. District biologists induce the females to lay their eggs, then incubate and hatch them, raising the young for two years before reintroducing them into the wild. The program tracks turtles using small injected microchips called PIT tags and radio transmitters that give the turtles the distinct look of being remote controlled.

Head Start emerged from a 1994 study that discovered older turtles, which can live as long as 70 years, were not being succeeded by younger generations. “We had a geriatric population,” Thompson says. Blanding’s turtles must survive to their teens before they can breed, and it seemed that most weren’t making it.

Throughout much of their range, populations of Blanding’s turtles are in decline as the wetland habitat the turtles need to live and breed becomes fragmented or disappears altogether. In DuPage County, says Thompson, “turtles are making longer treks to find suitable habitat, and when they find it they’re clustering along travel corridors for predators.” This puts nests and young squarely in the path of burgeoning populations of raccoons and mink, primary predators of turtle eggs. “The raccoons know when nesting season is, they know how to key in on the nests, and they go down very efficiently and prey on all of them,” says Thompson. Automobile collisions pose another major threat, as well as fishing accidents and poachers for the pet trade.

But despite such dangers, Blanding’s turtles aren’t timid about travel. They often make long journeys to find mates, good nest spots, and other resources. In the spring of 2004, Wildlife Ecologist Sue Hayden of the McHenry County Conservation District, which also has a Blanding’s program, discovered a male turtle that PIT tags suggest traveled at least eight miles during the past eight years, farther than any other Blanding’s turtle on record. The turtle would have had to swim along streams and ditches, traverse fields, cross busy roads, climb over berms, and avoid both farming equipment and predators. “If Blanding’s turtles can indeed travel these distances,” Hayden says, “then maybe in McHenry County they aren’t separate populations like we previously thought.” She allows that humans often play a role in such odysseys. The more typical Blanding’s voyage is less than a mile.

Blanding’s populations are still declining as the older turtles die, but improved techniques have allowed DuPage County to release nearly eight times more juveniles than when the program started. McHenry County will release turtles this year. Others are pursuing the Blanding’s challenge, including Will and Lake Counties, both involved in a major study of the turtles’ needs with the Illinois Natural History Survey.

Almost ten years since the first releases, Thompson hopes to see signs of reintroduced turtles reproducing naturally. But to assure long-term survival, conservationists stress the need for a comprehensive approach, possibly including predator control. Many are restoring large-scale preserves so the turtles can nest closer to home wetlands and away from popular wildlife corridors. “I think there’s no question that these turtles can coexist with humans,” says Thompson. “By tracking turtles and watching them nest in the field, we got a great idea of what their habitat requirements are, and we should be able to emulate that in restorations. All wildlife will benefit from saving this habitat.”

“The more you work with the Blanding’s turtle, the more you come to appreciate and admire it,” says Thompson. “When nights are quiet, I can hear the rustle of grass as they’re coming out of marsh.” The hushed signs of life surviving are closer than most of us realize.

Related Articles:

Head Start for Turtles (News of the Wild, Summer 1998)

Young Activist Aids Marsh and Blanding’s Turtles (News of the Wild, Summer 2003)

Emydoidea Blandingii on the Animal Diversity Web

Blanding’s Turtles in Wisconsin (Wisconsin DNR)