DELMARVA ALMANAC

Box Turtles

by Dave Wilson

Naturalist Dave Wilson discusses the lives and status of box turtles on Delmarva with fellow scientist Scott Smith.

Dave Wilson:
My guest today is Scott Smith. Scott has worked for the Maryland Department of Natural Resources for 26 years and is a Wildlife Ecologist for DNR's Natural Heritage Program. Scott currently conducts applied research and conservation efforts for reptiles and amphibians. He has a bachelor's degree in Natural Resources from the University of Rhode Island and a Masters in Wildlife Management from Frostburg State University. He lives on the Eastern Shore in Caroline County.

Scott, I want to start with the basics here. What is a box turtle and how is it different from other turtles?

Scott Smith:
"First Dave, I'd like to thank you for having me here. The box turtle is called a box turtle because its body is kind of like a box. It has a high dome shell and basically it's a box with legs, a long neck, and a tail. It has a bottom which we call the plastron that is hinged so it's able to close up its shell really, really tight, like closing up a box, when it's threatened by any type of predator. This is our only truly terrestrial turtle in Maryland. It's one of the 19 turtle species in the state. It spends the majority of its time on land whereas all the other turtles spend the majority of their time in water."

"It's very cryptically colored to fit in with the forest habitat that it lives in. It's a mixture of yellows and oranges and reds and greens and browns and blacks. If you think about what a closed canopy forest looks like, there are little gaps in the trees and leaves, and the sunlight hits the ground in a little dot pattern. That's kind of what their shell is designed to do. To help them hide in that type of habitat."


Dave Wilson:
Can you tell me a little bit about what turtles eat or maybe some of the habitat requirements they have as well?

Scott Smith:
"So we think of the box turtle as a turtle of open woodlands and fields. It depends on the time of year and where they are in their life and the habitat that they use. They overwinter in the ground in the forest litter underneath the leaf litter and the duff on the forest floor and then they come out in the spring and feed on things like mushrooms and fungi. And really they're an opportunistic feeder. They will feed on pretty much anything that's around whether they are berries, fruits, nuts, seeds, insects, insect larvae and even small mammals, particularly baby small mammals, or even frogs and salamanders and perhaps a dead fish or two--so they feed on carrion too."

"And also they use the forest and also pasture. And these forest/field ecotones, these edge habitats, because they need that open sun and also they lay their eggs in those open areas,--whether they're someone's suburban backyard, a pasture, an old field, a hayfield,--these habitats are important. They cover pretty much ground. They have a home range of about 40 acres per turtle."


Dave Wilson:
How old do box turtles get?

Scott Smith:
"Surprisingly there is one published account of a turtle getting to be 138 years old which is really phenomenal. Probably it's more realistic that they get to be 50 to 80 years old. Lucille Stickel, who's a famous person in the box turtle world, did work here in the Maryland Patuxent Wildlife Research Center over in Laurel in Prince George's County. She did a famous study that started back in the sixties and that has since been carried on by folks who followed up on her work so it's more than a 50-year study on box turtles there. And they found that the majority of the box turtles in that population only live 25 to 35 years. It's just those rare old-timers who make it between 50 and 80 years."

Dave Wilson:
What are some of the threats that they face?

Scott Smith:
"Like most other wildlife one of the big threats they face is habitat destruction and habitat fragmentation --the fragmentation particularly by roads. There is also illegal commercial collection for the pet trade of this species. There is an increasing threat from disease which I'll talk about in a minute. Road mortality is very big and even forest fires can cause problems as well as contaminants and even climate change."

Dave Wilson:
Do you have a sense of the status of box turtles in Maryland?

Scott Smith:
" The work done at Patuxent Wildlife Research Center is one of the longest data sets for box turtles anywhere and it shows that the population there has declined dramatically. You could say that is a green area embedded in a rapidly developing landscape which is the story for a big part of Maryland. So using that as an example we can assume that box turtle populations have declined in those types of areas."

"We just finished, here in Maryland, our Maryland Amphibian and Reptile Atlas project, which of course, Dave you were heavily involved in in Worcester County, and that data is interesting. It shows that box turtles are still the most common turtle in Maryland as far as their distribution. They are found in every county in the state and they're still everywhere but there is a sense, and it's an anecdotal sense that they've declined."


Dave Wilson:
Can you talk a little bit about rana virus? I know the virus of course has infected frogs but it's infected turtles as well.

Scott Smith:
"Really there's three big species that rana virus, which is a frog virus, has affected. Wood frogs and spotted salamanders, their larvae, and one turtle that is really being heavily impacted by it is the eastern box turtle. In fact, they're truly the one species that I have the most concern about because the frogs and salamanders are able to produce lots and lots of eggs. Box turtles really don't reproduce like that. They only lay eggs once a year and it's not very many eggs. And predators get most of those nests so anything that impacts box turtles is of concern."

Dave Wilson:
Do you know where rana virus came from? Is there good scientific evidence of that?

Scott Smith:
"No there is not. Right now there's still a lot of theory as to where it came from. It certainly started showing up in die-offs in the United States--actually North America--in the 1990s and there is some evidence that it first came here in the late 1960s. But it's possible that it may have always been here and there is a lot of stress out there in the environment that brings disease out."

"It's also possible that rana virus has changed. It is a very rare virus because it started in fish and it jumped to amphibians then it jumped to turtles, basically cold-blooded animals. We don't normally see that in most diseases. Most diseases are just in mammals or just in birds, or just in fish so it's a very interesting and potentially deadly disease.""


Dave Wilson:
What can folks do to protect box turtles?

Scott Smith:
"First and foremost protect habitat, and by habitat I mean large continuous areas of forests and fields. A single turtle has a home range of over 40 acres and we have lots of overlapping home ranges--really the bigger the better, just some landscape conservation. On your own property, let's say you're out there and you see one. It's great to observe them but just leave it alone. If it's in the wild leave it alone."

"Another example is crossing roads, which is a source of a lot of mortality. If it's safe for you to pull over and help that turtle across the road, put it off the side of the road in the direction it was going and you can help them out a lot. But you could also possibly on your own property (whether it's small or large) think about leaving an unmowed edge along forest habitat at least through the summer into the fall. That gives them an area to catch insects to feed and to nest."


Find out more:
Maryland's Turtles & Tortoises

Creating a Wild Backyard - Turtles in Maryland

Turtles in Trouble - Delaware Department of Natural Resources [PDF]

Eastern Box Turtle

Eastern Box Turtle - Virginia Herpetological Society

Box turtle - Wikipedia