Perhaps you found a wood turtle on your latest hike and are curious about its age. Or perhaps you have one that you’re keeping as a pet and you would like to determine how old it is. Whatever the reason for your search, you’ve come to the right place! In this article, we’ll discuss how to tell the age of a wood turtle and answer a few related questions.
What You'll Learn Today
How Fast Do Wood Turtles Grow?
Generally speaking, most turtles grow an average of one inch per year for the first several years of life; after that, their growth rate will gradually taper down until they stop growing altogether.
For the exact estimated growth rate of wood turtles, refer to a size chart in a field guide or books at your local library.
Again, though, keep in mind that any size chart is only an estimate. Turtles may grow at a faster or slower rate depending on various environmental factors.
For example, those that survive long periods of famine will grow much more slowly than those who never lack food. Wood turtles in captivity may grow up to four times as quickly as those in the wild because they will have much better care and more ideal conditions.
How Can You Tell the Age of a Wood Turtle?
Unless you know when the turtle hatched from its egg, it’s impossible to determine its age with complete accuracy.
That said, there are two primary methods that can be used to estimate a turtle’s age, particularly if the turtle is still fairly young. There are also other physical clues you can look for to determine whether the turtle is young or old.
Let’s take a closer look at each method.
One of the most common ways to estimate a turtle’s age is to count the rings on its shell. To do this, you’ll need to be aware of a few technical terms:
- Scutes: The scutes are the scales on a turtle’s shell. They typically look like large individual segments of the shell. On a wood turtle, each scute is triangular, a bit like a flat pyramid.
- Carapace: The carapace is the top part of a turtle’s shell. This is where you will find the wood turtle’s ringed, pyramid-shaped scutes.
- Plastron: This is the bottom part of a turtle’s shell–the belly or underside of the turtle. On a wood turtle, the plastron is divided into flat yellow scutes, and each scute has a black marking on the lower outside corner.
Examine the scutes on the carapace of the wood turtle in question. You will notice rings around each scute, similar to the rings of a tree.
Some of these rings may be wider, while others will be narrower. This is thought to represent times of plenty (such as summer when there is lots of food available) versus times of want (such as winter when wood turtles hibernate and eat very little).
Since these rings tend to develop about twice a year (summer and winter), you can count the rings within a scute and divide the number by two to reach an approximate age.
For example, If a turtle has 16 rings in each scute, it is probably about 8 years old. If there are 20 rings in each scute, it is probably about 10 years old.
Keep in mind that turtles, including wood turtles, may develop more or less than two rings per year. Ring development is based on food availability and is not strictly tied to the seasons.
A wood turtle that has an abundance of food year-round, such as one kept as a pet, may develop several rings per year, or it may develop one particularly wide ring.
Those that frequently face periods of famine may develop rings that are too narrow to count or may not accurately reflect the turtle’s age.
What’s more, turtles over the age of 15 develop much narrower rings regardless of food availability. The older they get, the harder it becomes to see and differentiate between the rings.
So, if you have a young wood turtle, this may be a reasonably accurate way to estimate its age. But if the turtle is older, you may have a harder time doing so.
This is another method mostly used for estimating the age of a young turtle. As mentioned above, a turtle’s growth rate can vary not only depending on its species but on its environmental conditions, so measuring its size isn’t necessarily an accurate indicator of the turtle’s age.
That said, if you know a wood turtle’s average growth rate, you can measure the turtle from the tip of its nose to the tip of its tail and compare it to the size chart.
Compare the size of the turtle to the age it is supposed to be at that size. This will give you a general idea of how old the turtle might be.
Again, environmental conditions can affect how large or small the turtle is.
What’s more, turtles stop growing when they reach maturity, so if your wood turtle has already stopped growing, you won’t be able to use this method effectively.
Examine the scutes on the wood turtle’s shell. Younger turtles typically have bright yellow-and-black fan-shaped patterns on each scute, while they will be a duller olive-green to brown color on older turtles.
Very young wood turtles will be quite small and gray-brown in color. They will develop brighter colors and patterns within the first year or two of life, so if you find one that is still gray-brown, chances are it hatched within the previous year or so.
Check out this video to get a better idea of what wood turtles look like:
To estimate the age of a wood turtle, you can count the rings within its scutes or measure its length. Neither of these methods is completely accurate, but they can both give you a general idea of whether your turtle is young or old.