Scientists at the Smithsonian's National Zoo and Conservation Biology Institute's campus in Front Royal work to conserve ecosystems and threatened wildlife species. One of their ongoing projects has been to study a specific population of wood turtles for over 20 years. WMRA's Randi B. Hagi reports.
It was a warm, sunny morning at the end of May – and the turtles were on the move.
[driving along gravel road]
CHRIS POLINSKI: You know, we've had some pretty hard rains the last couple of days – oh, there's a box turtle.
We were searching for turtles somewhere in the George Washington National Forest. For the protection of the reptiles, which are at risk of poaching for the illegal pet trade, I can't disclose our exact location. Chris Polinski, lab manager for the Smithsonian's Turtle Conservation Ecology Lab, stopped on the one-lane gravel road for a female box turtle. Flipping her over to look at her plastron, or belly –
POLINSKI: I was just trying to see if I could guess an age, right, so you can kind of count the annuli, or these little rings.
HAGI: Like a tree ring.
POLINSKI: Yes, like a tree ring … She could be 20 years old.
She was a beautiful little turtle – with a round, yellow-and-brown shell and yellow-plated legs – but not the species we were looking for. We drove on towards a stream known to be inhabited by wood turtles, a semi-terrestrial species found in the forests here and northwards to Canada.
Advocates have petitioned the U.S. Fish and Wildlife Service to list the wood turtle under the Endangered Species Act. These efforts have been unsuccessful so far, but the agency does recognize the threats posed to them by habitat loss and fragmentation, vehicles, the black market, and other pressures.
Just down the road –
POLINSKI: That looks like a wood turtle.
[birdsong, nearby stream flowing]
Polinski picked him up and estimated he was probably more than 20 years old. Wood turtles are named for how the brown plates on their shells resemble cross-cuts of wood. Their profile is flatter than a box turtle, and they can grow up to nine inches in length.
POLINSKI: He's got a pretty big noggin. … Yeah, he's hissing at me. He's like, "dude, I've had enough."
[turtle hisses quietly]
POLINSKI: So they come in sort of a variety of colors, at least their legs and neck – mostly orange. … Yeah, he's a good-looking turtle. He's definitely got some injuries, so some older injuries, maybe when he was younger, because the scutes are kind of –
Scutes are the plates of a turtle's shell.
POLINSKI: Yeah, they're off-center, they sort of shoot off, and there's definitely some gouges here. So maybe as a hatchling he got nipped by, I don't know, a raccoon or a coyote or something. … But he's got all of his limbs! … Oftentimes you'll find missing front limbs, and that's because male turtles will fight with other male turtles for territory or mates.
This was a "new" turtle – meaning he hadn't previously been captured by researchers and his shell notched for identification. Since this was just a scouting mission and not an official survey, we let him go, still anonymous.
[turtle scoots off into the underbrush]
As Public Affairs Specialist Ellie Tahmaseb explained, when they do a survey, the number of marked turtles they find helps them estimate how many of that species are around.
ELLIE TAHMASEB: You're essentially saying, how many unmarked versus marked ones are we seeing, and if you see more unmarked, your population is larger.
One of their insights from studying this spot for more than two decades is that the population here is pretty stable – not increasing like they might hope, but also not decreasing.
Next, we put on chest-high waders and headed into the stream with viewing buckets – five-gallon buckets with clear plastic bottoms that help you see past ripples in the water.
[water running over rocks]
POLINSKI: This spot right here is a good spot for wood turtles, right? It's a pool, the water starts to get a little deeper, it doesn't move as much, it's more still, and it's got this sort of underhanging bank structure, so I imagine you could fit 10, 15 wood turtles overwintering, just up underneath the bank.
I found fish and crawdads, but no turtles. Polinski went noodling under fallen trees – also, with no luck. As we headed back out of the forest, Polinski and Tahmaseb joked about how field work doesn't always yield a lot of results.
TAHMASEB: Like, what do I have to show for this? [pauses] Oh!
POLINSKI: Alright! One more turtle!
TAHMASEB: Is it a wood turtle?
POLINSKI: Yes!
This old lady's plastron was worn totally smooth, so we couldn't count the growth rings there. But she was marked with a method that's no longer used, where small holes are drilled through the keratin at the outer edge of the shell.
POLINSKI: I imagine they were notching them this way, maybe back in the 90s, and then she would have been an adult, so say 10, plus 30, so 40 minimum.
That brought our final count for the day to two wood turtles, two box turtles – three of them along the road.
POLINSKI: Which makes sense given that it's been raining over the last three or four days and they're looking to sun themselves. … In addition to that, it is nesting season for both species, so those turtles are going to be on the move, looking for soft, sandy soils to lay a clutch of eggs.
Conservationists consider North America a turtle biodiversity hotspot, being home to around 60 different species. But many of them, like wood turtles, are on the decline. We can help, though – by preserving natural habitats and keeping waterways clean. And, if you find one in the road and can stop safely, carry it across in the direction it was facing. It might be on its way to make more hatchlings.
