By Kathleen Berger, Executive Producer for Science and Technology
The probable rate of box turtles killed by vehicles is the driving force behind study that hopes to preserve box turtles.
“We don’t know the mortality rates of box turtles on Missouri roads,” said Stephen Blake, PhD, assistant professor of biology at Saint Louis University. “What we do know is that box turtles get hammered on roads.”
That’s probably not the first thing people think about when they think of box turtles! Many people think of their fond turtle encounters and memories.
“Turtles play a very important role in society in people’s psyche,” said Blake. “Kids love box turtles. It’s a magical moment when a child finds a box turtle, and it’s a magical moment for many adults when they find a box turtle.”
Blake wants people to hold on to those endearing thoughts because he wants them to also think about what’s happening to box turtles as a result of sprawling cities and rapidly growing rural communities.
“Turtles are under significant threat from roads and are likely changing their ranging characteristics dramatically in relation to road infrastructure.”
Box turtle safaris in Forest Park allow students from schools in the region to understand turtles and study them after successfully tracking them. The students are observers of how Blake and his team are conducting box turtle research at Forest Park, which take dangerous road crossings for the turtles into consideration.
“We fitted radio telemetry tags to a sample of, originally, 10 box turtles in Forest Park, in different forest fragments,” said Blake. “And (another) 10 on box turtles at Tyson Research Center. And each VHF very high frequency radio unit emits a unique signal. So, with a radio receiver, we can follow the movements of each individual turtle.”
Blake teamed up with Sharon Deem, DVM, PhD, on the Box Turtle Project. Deem is the director of the Saint Louis Zoo Institute for Conservation Medicine.
“Everyone has a turtle story, right? These little iconic creatures, they really touch our hearts. Here in St. Louis, I haven’t met anyone yet who doesn’t have a turtle story to share with me,” said Deem.
Saint Louis University (SLU) and the Saint Louis Zoo are working together to preserve box turtles. They spent years studying box turtle movements.
“Eleven years we’ve been chasing little box turtles. During that time, we’ve looked here in Forest Park at the home range sizes where these animals are moving. As well as out at Tyson, this contiguous, wonderful oak-hickory forest,” said Deem.
“And when we find a turtle, we can locate it, actually physically find it, we record a GPS location of where that turtle is. And over time, we can build up a picture of the ranging metrics and movements of all of those turtles,” Blake explained.
Blake is the lead author and one of the principal investigators along with Sharon Deem of the recently published study.
“Box turtles at Tyson Research Center cover a lot more ground. They have much bigger home ranges than the box turtles in Forest Park. So, the turtles that are living in Forest Park are probably those that have learned to have restricted ranges within the small forest fragments,” said Blake.
“I think the really exciting, unique part of this study is what the team did under Dr. Blake’s leadership with looking at Missouri roads, so the road system here in our state,” said Deem. “And then doing iterations of placing one of those turtles, Kevin or Kimmy or pick your turtle, placing them on the map and doing their home range and seeing how many times that turtle would cross a road. And we see even with the turtle with the smallest home range, they will cross a road a number of times each year. In the larger home range, they’re always crossing roads.”
“A turtle at Tyson Research Center, if you put that (turtle) randomly anywhere in Missouri, is going to be crossing roads. 100% of the time,” said Blake.
The findings show that the Forest Park turtles, that have learned to live in the restricted home ranges, would not cross as many roads as a less restricted Tyson box turtle that would travel longer distances. But the more restricted box turtles, like the Forest Park box turtles, would still cross roadways about five times a year. The researchers encourage some basic conservation efforts.
“If we’re going to expand urban areas, we need to do it in a way that includes a matrix of wildlife habitat. Within and around increasing urbanization, we need to think about traffic volume.”
Blake said there is one thing everyone can do!
“If you see a box turtle in the road when you’re driving or when you’re walking, and it’s safe to do so, pull over, pick the turtle up. If you pick a turtle up and turn it around and try and get it to go in the wrong direction, it’s gonna want to go in the direction that it wants to go in,” Blake explained. “So, you should take it to the side of the road in the direction that it’s already going, let it go and you’ll reduce the chances of that turtle being killed by traffic enormously.”