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How do you save the beloved box turtle? A 100-year-long study

Ann Berry Somers, shown here at a research camp in 2018, helped start what could end up being the biggest, longest study of box turtles ever.
Martin Kane/University of North Carolina at Greensboro
Ann Berry Somers, shown here at a research camp in 2018, helped start what could end up being the biggest, longest study of box turtles ever.

When Ann Berry Somers was 7 years old and growing up in North Carolina, she encountered a box turtle on a path. She picked up the small reptile and looked into its eyes. Instead of retreating into its shell, the turtle gazed back. It felt like she and the turtle were sharing a moment of connection.

"I was just mesmerized by the fact that there was this beautiful creature that allowed me to touch them," she says. "I was so full of amazement and gratitude for that experience that it stuck with me."

A half-dozen subspecies of box turtles make their homes across much of the U.S., from Maine down to Florida and westward out to Colorado. With their bright eyes, colorful carapaces and calm demeanor, these wrinkled denizens of the forest have historically provided E. T.-type experiences to children exploring back yards, forests and other green spaces. But some turtle fans, like Somers, worry that those special moments are becoming increasingly rare.

Now 70 and retired from the University of North Carolina, Greensboro, she's still highly attuned to box turtles, like a battered one she recently spotted near her driveway. This particular adult male had lost a few toes on one foot, maybe to a hungry raccoon, and had a beat-up shell. But the shell's edge had a set of unique identifying notches – marks that identified this turtle as part of an ambitious project that Somers helped start in her home state, one that could end up being the biggest and most long-term study of box turtles ever.

Two children hold a female eastern box turtle in this early 20th century photograph. Despite popular interest in box turtles for over a century, scientists don't know how populations have changed over time.
/ From the collection of Zachary Cava
/
From the collection of Zachary Cava
Two children hold a female eastern box turtle in this early 20th century photograph. Despite popular interest in box turtles for over a century, scientists don't know how populations have changed over time.

Called the Box Turtle Connection, its goal is to monitor thousands of box turtles for at least 100 years, which means that eventually the work will have to get passed on to people who are currently children having their own formative moments with turtles. Already, since 2008, dozens of volunteers have collected information on over 4,100 box turtles living on over 30 sites across North Carolina, from private properties to vast state parks.

By looking in its database, Somers could tell that her driveway turtle had last been found two years earlier in almost the exact same place. "It couldn't have been 15 feet from where we found it before," says Somers, who delightedly explains that box turtles are homebodies that can spend their entire lives in a few acres. (Somers has stuck close to home herself, as she was raised about ten miles away.)

Gently cradling the turtle in her hands and admiring its bright orange neck, Somers says, "I'm certain it's more than 20 years old, but how old, I can't tell you. And anybody else that tells you that they can tell, I wouldn't believe much else what they said."

Determining a turtle's age is a tricky business, because the lines of growth on its shell aren't as revealing as the growth rings inside a tree. Clearly, though, living a century is a possibility. Researchers in Long Island, NY found a turtle in 2002 with markings on its bottom shell that showed it had been captured in 1921 by a naturalist who, back then, recorded that it was a couple of decades old.

This is one of the best-documented centenarian box turtles, found in 2002 with markings on its shell made in 1921 by a naturalist who had judged it to be at least 20.
/ David Brotherton
/
David Brotherton
This is one of the best-documented centenarian box turtles, found in 2002 with markings on its shell made in 1921 by a naturalist who had judged it to be at least 20.

"It's a lifespan similar to a human lifespan," says Somers. "Humans can live to be a hundred years old easily, if conditions are right."

Unfortunately, conditions increasingly aren't right for box turtles.

The very name of the "common box turtle" seems to imply that it's widespread and doing fine. "The reality is, we just don't know," says herpetologist C. Kenneth Dodd, Jr., who literally wrote the book on box turtles, entitled North American Box Turtles: A Natural History.

Biologists do know that all around the world, turtles are in trouble. A global assessment of reptiles published this year concluded that 58 percent of turtle species are at risk of extinction.

That's why Somers and her partners want to know the beloved box turtle is faring. They believe a really, really long-term study over a diverse array of habitats is the only way to find out.

Gabrielle Graeter, a biologist with the North Carolina Wildlife Resources Commission, shows volunteers on how to properly fill out data sheets with box turtle information.
/ Jeff Hall
/
Jeff Hall
Gabrielle Graeter, a biologist with the North Carolina Wildlife Resources Commission, shows volunteers on how to properly fill out data sheets with box turtle information.

Somers says they don't actively try to recruit volunteers, but wait for people to hear about it and just show up. She believes that's the best way to get folks who are serious about staying with it, slow and steady, for the long-haul.

"I say, 'Well, you've got to make a long-term commitment,' and they say, 'Well, how long?'" explains Somers. "And I go, 'Well, lifetime would be nice.'"

From lawnmowers to criminal syndicates

Box turtles face serious known threats. Lawn mowers, tractors, and cars are constant killers. Bulldozers have razed significant amounts of their habitat, turning forests and meadows into houses and roads and shopping centers. Emerging infectious diseases, such as ranaviruses, have turtle experts worried about the potential for mass die-offs.

What's more, lots of box turtles simply get picked up and stolen. These charismatic reptiles go for big bucks in the pet trade. In May, for example, one man in North Carolina pled guilty to gathering and selling at least 722 box turtles, plus 125 other turtles, for an estimated $121,000.

A few long term studies of box turtles have documented population declines. But those studies have looked at relatively small geographic areas, like a single wildlife refuge, that might not reflect broader trends. And across huge swaths of box turtles' natural range, says Dodd, no one has been paying attention at all.

Box turtle shell markings come in many different patterns.
/ Top left, clockwise: Matthew Beziat/Flickr; Nancy Magnusson/Flickr; David Yeany/iNaturalist; ekabay/iNaturalist; mikedmeister/iNaturalist
/
Top left, clockwise: Matthew Beziat/Flickr; Nancy Magnusson/Flickr; David Yeany/iNaturalist; ekabay/iNaturalist; mikedmeister/iNaturalist
Box turtle shell markings come in many different patterns.

That's why he applauds North Carolina's effort to take a century-long look, even if the study's sheer size and scope will produce data that's a little messy. Rather than relying on one standard method to find turtles, for example, some volunteers use trained dogs, others do methodical surveys, and some just log information on box turtles that they happen to come across by chance. That means there's no easy way to capture the total amount of time spent looking for turtles, which is important for certain kinds of population analyses.

"The study's not perfect – but then, no study is going to be perfect over that period of time that's necessary, or that area that needs to be covered," says Dodd, noting that short-term studies just don't cut it for box turtles, given that it takes each animal about a decade to reach sexuality maturity and be capable of reproducing.

Much about box turtles remains mysterious, even to Dodd. A few weeks ago, he came across a box turtle in his yard in Florida.

"Now, I've lived in my house for 37 years. I've never seen this box turtle before," he says. "You wonder how many others are walking around our area, and we just don't know how they go about their lives."

Powerful, aggressive interactions

John Roe once found 8 box turtles on a rainy, late-summer day. Over the last decade, he's developed an uncanny ability to perceive them despite their ability to blend in with the yellow and brown leaves on the forest floor.

"There's certain turtles that I encounter frequently enough that I get to know," says Roe, a biologist at the University of North Carolina, Pembroke. "Sometimes I'll come across a turtle and I'll instantly recognize who it is."

John Roe (left), a biologist at the University of North Carolina, Pembroke, works with students to track and log box turtles.
/ Nell Greenfieldboyce/NPR
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Nell Greenfieldboyce/NPR
John Roe (left), a biologist at the University of North Carolina, Pembroke, works with students to track and log box turtles.

The turtles aren't always alone, and Roe has witnessed violent fights. "They're climbing on top of one another, they're turning each other over onto their backs," he says, "and then they're biting, they're scratching, they're taking chunks out of each other's shells at times. It's pretty powerful, aggressive interactions."

One morning this summer, he and a few students spread out and began to walk through trees, keeping their eyes on the ground. Roe doesn't want the site's location to be revealed, for fear of attracting wildlife traffickers.

"It recently rained and you have a lot of mushrooms growing, and that's one of their preferred food items," says Roe. "They should be out and active."

Before too long, he spots a small one that looks like an adult male. "It's got a more colorful head, and you can see a little bit more of a reddish eye," says Roe.

Notches on its shell's edge show that it's been captured before, and Roe looks up its records. "This turtle was originally caught in 2015, again in 2016," he says, noting that it was already an adult when first captured; that means it should be at least 15 years old.

A few long-term studies of box turtles have documented population declines over decades, but those looked at one small area, not a vast state like North Carolina.
/ Nell Greenfieldboyce/NPR
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Nell Greenfieldboyce/NPR
A few long-term studies of box turtles have documented population declines over decades, but those looked at one small area, not a vast state like North Carolina.
(Left) Notches filed along the rim of a turtle's shell allow it to be identified by researchers over time. This turtle TKTKT (is estimated to be 26 years old?)
/ Nell Greenfieldboyce/NPR
/
Nell Greenfieldboyce/NPR
Left: Notches filed along the rim of a turtle's shell allow it to be identified by researchers over time.

On this, its third meeting with researchers, the turtle patiently endures the same standard protocols as before. Roe and his students record the turtle's exact location, measure its shell, weigh it, check for any signs of disease or damage, and take a photograph.

Years ago, when Roe first heard Somers talking about her plans for a century-long, state-wide study, he was intrigued but skeptical. "I really doubted how long-term we could carry it on for," he says. But then he went to the first training meeting for volunteers and saw their enthusiasm. "That convinced me otherwise. I thought that this project does have a chance." Now he sports a T-shirt with the project's logo and the caption, "10 down, 90 to go."

Roe recently analyzed the study's first ten years of data and found that North Carolina's box turtle populations seem to be holding their own--at least so far.

"There wasn't a consistent trend at any site of growth or decline, and nothing was statistically different from the beginning of the study until where we are now," says Roe. "Everything was relatively stable, which is good news – but I don't think we should get complacent about that."

After all, ten years isn't much given the lifespan of a turtle. And who knows how many losses occurred in the years before the study began? Plus, many of the study's sites are in state parks, which could offer these particular turtles a certain amount of protection that others don't enjoy.

Roe also points out that apparent stability can abruptly disappear. One wildlife refuge in Florida had a large and seemingly healthy box turtle population that dwindled to almost nothing after a wildfire.

In addition, the North Carolina study found that the density of box turtles seemed to be lower in places surrounded by more urban development, suggesting that what happens outside of parkland can affect the turtles inside.

"Turtles themselves don't know where these borders are," says Roe. "They cross over them all the time, and get themselves into threatening situations like crossing roads or walking into people's backyards."

Follow the beeps

At the North Carolina Arboretum, education outreach manager Trudie Henninger slowly moves through the woods, holding an antenna that receives radio signals. "With this, we can actually follow the beeps to a turtle," she explains.

That's because some of the study's box turtles have radio transmitters stuck onto their shells, so researchers can track their movements more closely and learn how the turtles use their home base over time.

One way the project is tracking individual turtles is through radio transmitters attached to the turtle's shell.
/ Sue Miller
/
Sue Miller
One way the project is tracking individual turtles is through radio transmitters attached to the turtle's shell.

One particular turtle here, for example, usually likes to hang out in the gardens but makes an annual trek each summer down to the wetter, boggy areas of this preserve.

The importance of wetlands is one of things that this long-term study has already made clear, says Gabrielle Graeter, a conservation biologist and herpetologist with the North Carolina Wildlife Resources Commission. Box turtle densities were lower in areas without access to wetter habitat.

"People don't often think about them being in wetlands or even, like, on the edges of rivers. I've found box turtles congregated in little muddy patches right on the edge of a swift, large river," says Graeter. "We find them in springs, down in little streams. I really think the water component is important."

Given that they can spend decades wandering in a home area that's generally only 2.5 to 12.5 acres, box turtles must develop a kind of inner map of important resources like water and seasonal food. That's why Graeter says it's a bad idea to pick a turtle up and move it someplace else.

"It may not look like the best place for it, but that's its home, and it needs to be left where it is," she says. "Moving them elsewhere can be very disorienting, it can result in them trying to get back to where they are from."

That's true even if box turtles appear to be sick or have injuries, because turtles have a remarkable ability to heal themselves. "Most turtles should be left out in the wild," says Brian Bockhahn, an educational specialist with North Carolina State Parks.

The one exception is if a box turtle is spotted as it tries to cross a road. Helping it across, if that's a safe thing to attempt in traffic, can keep it from becoming roadkill.

"Look at which way it's facing," says Graeter. "That's the direction it wants to go."

At the arboretum, Henninger and Graeter follow radio transmitter beeps to an area planted with tall grasses. Bockhahn hunts through the mounds of grass and finds a female box turtle with a thin antenna sticking up from a small device plastered to her shell.

"I like to look at a turtle and just imagine the wisdom it has of this place that I might be passing through," says Henninger, who has a turtle tattooed on her arm.

Her records show that the first time this particular turtle was captured was in 2013. That, the turtle's appearance, suggests an age of at least 25.

Later, a group of far younger children troops past the turtle's grassy hiding spot.

"Do any of you like turtles?" asks Bockhahn, and several kids say, "Yeah!"

"On the count of three, say 'I like turtles,'" says Bockhahn, leading the children in gleeful shout-out. "I like turtles!" the kids scream.

Some day, one of them might end up as a volunteer for the Box Turtle Connection project, which still has 86 years to go.

And, if so, maybe one of them will live long enough to see the opening of a time capsule in the year 2108. Somers and her colleagues are about to have it built in a state park. Plans show a rectangle made of stone that will house two sealed metal canisters.

"This is the plaque that's going to be on there," says Somers, reading the inscription aloud: "Dedicated to the Box Turtle Connection project leaders, past, present, and future."

Somers isn't sure yet what will go inside the capsule, except for letters from current volunteers to future ones. She hasn't written her note yet, but she will.

Copyright 2022 NPR. To see more, visit https://www.npr.org.

Nell Greenfieldboyce is a NPR science correspondent.