Rare Blanding’s turtle thrives in Ohio’s wetlands as conservation efforts continue

A turtle perches on a log at Sheldon Marsh in Huron with its bright yellow neck stretched over the water and its mouth curved into what looks like a contented smile.

The turtle’s brown, domed shell is flecked with yellow dots, and there is a small notch in the side of it. The animal seems oblivious to the two birders standing on the road, excitedly watching it and snapping its picture.

The turtle bends its head toward the water and dips in for a cooling splash on the hot spring day.

This turtle is unusual because it is a Blanding’s turtle, a threatened species in Ohio that is being considered for listing as a federal endangered species. In Ohio, it is found only in marshes along Lake Erie in the Oak Openings region in Northwest Ohio stretching to the Indiana State line.

The upside-down U- shape of the notch in the Sheldon Marsh turtle’s shell, captured by one of the birders in a photo and sent to the Toledo Zoo along with the date and location of the turtle sighting, will help researchers determine when and where the turtle was tagged.

Toledo ZooBlanding’s turtles are most easily recognized by their bright yellow throat and their mouths, which always look like they are smiling. “You think about something that lives for 90 years. If you only study it for a year or two, you only get a snapshot really,” says Matt Cross, Director of Vertebrate Conservation at the Toledo Zoo, which studies a variety of Ohio turtles, including the Blanding’s. “We’re really in a position to do these long-term studies.”

Years of logged information about the turtle’s movements, age and other factors help the Zoo and its partners – Ohio State University’s Ohio Biological Conservation Partnership, Michigan State University Michigan Natural Features Inventory, Purdue University – Fort Wayne, and the Ohio Division of Wildlife – determine how the turtles’ populations are doing and what challenges they face. The zoo has been tracking these animals since the mid-2000s.

The goal is to help these turtles rebound and grow to healthy numbers in a wider range.

“We are still concerned about the long-term sustainability of the Blanding’s turtles,” says Cross, who has worked with the species at Toledo Zoo since 2016.

Thankfully, the turtle is a charismatic species that tends to endear itself to nature enthusiasts who are willing to help. 

“I think, in general, people are pretty enamored with Blanding’s turtles,” Cross says. “They’re really on board with their conservation. We have so many birders and park conservationists who see Blanding’s turtles when they’re out enjoying nature.”

A secretive, charismatic species

Blanding’s are most often found in the Lake Erie marshes, sitting on logs or sticking their heads out of shallow waters. 

“They tend to prefer early season with wetlands that dry up eventually where they can chow down on tadpoles, crayfish, and things like that,” Cross says. “They’re mostly going to be aquatic foragers.”

Magee Marsh Wildlife Area has a population of the turtles in its marshes.

“I would consider them a common sight from the boardwalk in the spring,” says Kelly Schott, Education Specialist at Magee Marsh for the Ohio Department of Natural Resources, Division of Wildlife. “They seem to be more secretive in the summer. Many spring birders have become accustomed to seeing them in the spring and look for them.”

Kristina SmithA Blanding's turtle is spotted at Sheldon Marsh State Nature Preserve in May.Blanding’s turtles are most easily recognized by their bright yellow throat and their mouths, which always look like they are smiling. They have a domed shell, like a box turtle, and spots on the shell that can sometimes cause them to be confused with spotted turtles.

“It’s just the way their beak is shaped,” Cross says of the turtle’s smile, which is one of the reasons people tend to like it. “Turtles in general, to me, are a very charismatic species. If I’d have to pick the most charismatic of our locale, it would be the Blanding’s.”

The turtles don’t become sexually mature and able to reproduce until they reach 10 to 15 years, and their lifespan appears to be at least 90 years. They can grow to roughly the size of a football.

Researchers don’t know for sure how long the turtles live. In the future, having long-term tracking data should be able to help them determine that.

For example, the University of Michigan’s Edwin S. George Reserve, about 25 miles north of Ann Arbor, has monitored the Blanding’s since the 1950s. Thanks to decades of data, researchers recaptured a turtle that they estimated was 94 but could be well over 100 years old.

Blanding’s also tend to look youthful, no matter how old they are. That 94-year-old turtle looked the same as the young turtles the zoo and its partners have captured, studied and released along the Lake Erie marshes, Cross says.

Threats to the Blanding’s

Blanding’s turtles are mostly a Great Lakes species that stretches as far west as Iowa but also has been found in the northeast, from Pennsylvania to New England, Cross says. In each of these locations, they have a varying degree of state protection.

Their numbers have declined in past decades because of habitat loss. Ohio has lost 92 percent of its historic wetlands, Cross says. Much of the lakefront marsh habitat they prefer has been developed into waterfront homes or used for beach and related recreation.

Mortality from cars, especially along the heavily traveled Ohio 2 around Oak Harbor and past Ottawa National Wildlife Refuge and Magee Marsh Wildlife Area, is a major concern.

“Turtles in general like to nest in open, loose, well-drained soil,” Cross says. “Blanding’s are kind of an oddity where they tend to move farther to find nesting habitat, upwards of a kilometer from where they tend to hang out. That puts them at greater risk.”

Private landowners and existing protected wetlands are working to preserve and restore wetland habitat, which should help the Blanding’s turtles, as well as other species, Cross says.

Kristina SmithBlanding's turtles can grow to roughly the size of a football.In addition to facing habitat loss, the turtles have plenty of predators. Raccoons are the biggest one, and they can decimate an entire clutch of turtle eggs at once by chowing on one after the other, Cross says. Birds, otters and dogs also are predators. 

Blanding’s turtles tend to lay one clutch of eight to 18 eggs per year, so a predator raiding multiple nests or killing young hatchlings can have a big negative impact on young turtles. 

Temperature also can impact on young turtles. Eggs exposed to higher temperatures tend to produce female turtles, while those with cooler temperatures tend to produce males, Cross says. 

Long-term, having too many of one sex and not enough to continue reproducing a healthy population of turtles could be a concern. Researchers don’t have enough historical information on this yet, which is another reason tracking the turtles over many years and developing a long data set is important, Cross says.

Hatching Blanding’s, tracking turtles

To get that data set, the zoo uses multiple approaches and has been tracking the Blanding’s since the mid-2000s. 

Researchers collect eggs from turtle nests and bring them back to the zoo to hatch there. They are later released into areas where they historically lived or transferred to another facility where they grow for another year before being released. 

The turtles are tagged, similarly to how dogs and cats are microchipped, and receive shell notches. This way, those that are caught for study before being released can be tracked through their tag, or some that are photographed or video by nature enthusiasts can be checked for notches. Some turtles are also fitted with radio transmitters to track their movements.

Researchers will set live traps for the turtles in the marshes and collect information about them before releasing them. All of this goes into a database of information, including each turtle’s sex, size, age and more. 

From 2019 to 2021, researchers trapped 588 Blanding’s turtles over 47 sites. They also catch and monitor other species of turtles, including box, spotted, painted and snapping turtles, and have amassed the largest data set of turtle information in Ohio, according to the zoo. 

Catching the young turtles is a challenge, Cross says. For whatever the reasons, they avoid traps. Additionally, the adults’ ability to maintain their youthful appearance through the years makes it difficult to know how old untagged turtles are.

As their work continues, researchers are evaluating their practices to determine what works best for advancing their studies and conservation of the animals.

“It’s a project we’re all really passionate about and really enjoy,” Cross says.

The public’s help has been important, those who see the turtles are encouraged to report their sightings, including location, date and any photos or videos, to the zoo at [email protected] or to ODNR at https://survey123.arcgis.com/share/987f2ade0037405ea9ff1819aab040a8?portalUrl=https://gis.ohiodnr.gov/portal. 

“It’s very easy to get people on board with the conservation of the Blanding’s turtle,” Cross says. “They make a really good model organism for our wetlands. They’re a really good ambassador species for conservation of wetlands and issues facing our wetland species.”

Want to see a Blanding’s turtle? There are some in Toledo Zoo’s native turtle area.