The release of a rehabilitated critter back into the wild is always a happy occasion at the Willowbrook Wildlife Center in Glen Ellyn. But when four young Blanding’s turtles scuttled off recently to begin new lives in forest preserve wetlands, it was extra-special cause for celebration.
Hatched last year from eggs incubated at the wildlife center and nurtured for months by Willowbrook staff and volunteers, the turtles were living proof that the DuPage County Forest Preserve District’s program to increase the county’s Blanding’s turtle population is off to a successful start.
“It was a good feeling to see my kids going out into the great big world,” said Kevin Luby, a forest preserve ranger who helped launch the turtle conservation project.”We had given them a great start. They were only a year old, but they were already as big as a 3-year-old Blanding’s turtle that had grown up in the wild.”
Though Blanding’s turtles are not on federal lists of endangered or threatened species, populations of the yellow-throated reptiles have declined sharply throughout the six-county Chicago area and elsewhere in recent years due to habitat destruction, according to Sandy Heyn, senior wildlife keeper at Willowbrook.
In recent years the 10-inch-long turtles, named for the Philadelphia doctor who discovered them in the early 1800s, have been added to the Illinois Endangered Species Protection Board’s “watch list,” and the U.S. Fish and Wildlife Service has warned that their numbers are dwindling. Female turtles are particularly at risk because of their egg-laying habits.
“During egg-laying time, females leave protected marshy areas and go in search of sandy soil,” Heyn said. In DuPage County, that often means crossing the Illinois Prairie Path, where they can be run over by bikers or picked up by hikers and taken home as pets.
At the few DuPage County forest preserves where Blanding’s turtles have been sighted, males outnumber females by as much as 9 to 1, according to Heyn. (To protect the turtles, forest preserve employees declined to identify specific areas known to harbor Blanding’s populations.)
To give the turtles a helping hand, district ecologists launched a program last year in which female turtles are caught and taken to Willowbrook Wildlife Center, where they are X-rayed to determine if they are carrying eggs. Egg-bearing females are injected with a hormone that induces laying; once laid, the cream-colored eggs are incubated in a mixture of vermiculite and water until they hatch, about 80 days later.
Forty eggs are being incubated at Willowbrook now and are expected to hatch within the next few weeks, Luby said.
Once hatched, the tiny turtles will spend a year at Willowbrook before being released into area wetlands to augment the county’s current Blanding’s turtle population, which is believed to hover around 80.
“Eighty may sound like a lot, but compared to the numbers of other species of turtles that are in the preserves, that number is very low,” Luby said. “There are thousands of snapping turtles in the preserves, for example.”
According to district animal ecologist Dan Ludwig, the captive rearing accelerates the turtles’ growth, reduces the chances that vulnerable young specimens will fall prey to predators and increases their odds of survival.
Blanding’s turtles can live as long as 60 or 70 years, according to wildlife experts, but generally do not begin breeding until they are about 13 years old. Ecologists hope that giving the turtles a healthful head start may speed up their sexual development.
“The hope is that once these young are released back into the wild, they will begin breeding in 10 years instead of the usual 13 to 18 years, and replenish the dwindling population,” Ludwig said.
The Willowbrook-reared turtles’ progress will be monitored via tiny radio transmitters painlessly secured to their domed shells with dental acrylic. Blanding’s turtles found on area preserves also have been fitted with the devices as part of a wildlife research program being conducted by Cory Rubin, a graduate student at the University of Illinois at Urbana-Champaign who is working with the forest preserve on the project.
“We go out daily with a hand-held radio receiver and track the turtles to determine what habitat they are in and what they are doing,” Rubin said. “Right now we have up to 25 turtles with radios on.”
