A threatened turtle species has personality. Knowing that could help them survive

Would you go sky diving? Strike up a conversation with a stranger? Volunteer to sing on stage? If you say yes, chances are you’re probably a bold person.

It turns out ornate box turtles — a threatened species in Iowa — can be bold, too, according to recent research from Coe College and other collaborators. The first-of-its-kind study revealed that the turtles have personalities, and those personalities can shape how the reptiles survive in the wild.

Ornate box turtles typically live in grasslands from North Dakota down to Texas and over to Indiana, including Iowa prairies that have shrunk by more than 99 percent from their once estimated 23 million acres. The turtles can live up to 50 years and grow to about 6 inches long, munching on insects and fruits. Their domed shells are adorned with shades of brown.

Benjamin Reed, now an assistant professor of biology at Washburn University in Topeka, Kan., laid the groundwork for investigating three turtle personality traits: boldness, activity and exploration. He started with one ornate box turtle population in 2016. By 2021 and 2022, his methods were being replicated in four populations in Iowa, Kansas and Nebraska with a team of other researchers and undergraduate students.

The research was published in the peer-reviewed journal Behavioral Ecology and Sociobiology this summer, marking the first project to investigate ornate box turtle personalities, said Danny Hughes an assistant professor of biology at Coe College in Cedar Rapids and co-senior author of the research. Its findings could help us better understand and protect this threatened species in Iowa.

“They do similar things that humans do,” Hughes said. “What other aspects of their biology can we learn?”

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Personality trials

Teasing out turtle personalities takes creative — yet simple — methods.

It started with researchers exploring every nook and cranny at the field sites for ornate box turtles. Once found, most turtles were tagged with a radio transmitter. That way, they could be found each year for long-term analysis.

Random samples of tagged turtles were collected from each of the four field sites and brought to the lab. There, trials commenced in three parts to test each personality trait.

Individuals were first placed in “arenas,” or kiddie pools, under a wooden den that was supposed to mimic their burrows in the wild. Researchers kept track over 10 minutes of how long it took for each turtle to fully emerge. The quicker it came out, the bolder the turtle was presumed.

“As you would expect, a really bold turtle turns around and walks straight out as soon as you put it in,” Hughes said, “whereas a shy turtle may never come out of the den.”

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The second test of the trial measured how active each turtle was. Researchers placed a tire rim in the center of the arena, creating a circular walking track for the turtles. From above, it area was divided into four quadrants.

Ornate box turtles tend to walk along walls until they find an exit. Active turtles will keep following the continuous loop, whereas inactive turtles may not walk at all in the 10-minute trial. Researchers recorded how many times the turtles switched quadrants — the higher the number of transitions, the more active turtles were labeled.

The final test took place in a square arena separated into four rooms. Each room was connected with small arched doorways.

“If they're actually deciding to go from quadrant one and quadrant two, they're basically exploring a new room,” Hughes said. “The number of quadrants that they enter in 10 minutes gives us a proxy for how exploratory they might be in the wild.”

Researchers repeated the trial twice with each turtle each year. After the tests were completed, the turtles were released exactly where they were found.

Trials are successful

Before they could even explore ornate box turtle personalities, researchers had to establish if the turtles even had personalities in the first place. They looked for repeated behaviors — which is how humans typically identify personalities — per turtle.

They found both repeated and variable behavioral data. But, for both short-term and long-term time frames, the amount of repeatability was higher than that of variation. That means the behaviors were happening more frequently than they weren’t, suggesting long-term patterns. And thus, the existence of ornate box turtle personalities was established.

With that, the researchers then could ask: How do turtle personality traits differ between each population?

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They found that personalities are not linked to turtle sex or body size, and average behavior varies across sites.

For example, Iowa’s ornate box turtle population was especially bold. On average, they came out of their dens at least a minute faster than turtles in other populations.

A Kansas turtle population that lives on a cattle ranch in North Topeka, on the other hand, was much shyer. That could be to protect themselves from cows stepping on them, suggesting that differences in turtle habitats may be driving behavioral traits.

“They're basically not a monolith, right? A turtle’s not a turtle’s not a turtle,” Hughes said. “At the population level, body size and sex don't seem to play a role. It's really something going on with the habitats, the ecology, and that sets us up for future work trying to explore those evolutionary outcomes.”

Future research and conservation

Now that they’ve established that ornate box turtles have personalities, researchers want to understand how those personalities impact the reptiles’ success in the wild.

The team is comparing the personality results to transmitter data that shows turtle movement patterns, ranges, survival rates, mating activities and nesting activities.

“We're working towards connecting personality to evolutionary success,” Hughes said. “Because you are what you are — boldness, active, exploratory — is this leading to better outcomes?”

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For instance, do bolder turtles have a bigger home range? How many habitats do they utilize? What turtles die — and is it related to their behaviors? Better understanding turtle behavior in the wild can better protect their populations.

Most of the turtles in the study, if not all of them, live in areas already managed for game animals.

“We have the power to manipulate the habitat in ways that are beneficial to animals,” Hughes said. “If we now can have information about the differences in personality or behavior that are linked to what they use in their habitat, and we control the habitat, we can then change it to improve the situation for these individuals.”

Brittney J. Miller is the Energy & Environment Reporter for The Gazette and a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues.

Comments: (319) 398-8370; brittney.miller@thegazette.com