The first time I met this turtle was about eight years ago. We were walking in the forest with our then pre-teen children and trying to get them to take an interest in their surroundings. So we offered five dollars to the first one who spotted a Box turtle. I already knew a goodly number of boxies lived in this little forest, and was not surprised when ten minutes later my son yelled in triumph upon finding this big old female.
My son is in college now and looks very different from the kid he was then. But those eight years meant very little to this box turtle, who I’m guessing is at least fifty years old and likely a decade or two past that. We may be the same age, she and I, which is an intriguing thought since I’ve hung out in these woods since I was a teen.
She has seen changes to her home, as the tree canopy closed over what used to be a more open landscape. Invasive Bush honeysuckle came to dominate the understory, creating deep shade. Now, ash trees are falling, the honeysuckle will be all gone in three more years, and the forest is once again becoming an open grassy woodland. Does any of this matter to her? She has spent her decades in a home range no bigger than a football field, and other than finding a sunny place to dig her nests each summer, she has likely not left it.
Our second meeting was yesterday morning. She was crossing the trail after a rain, probably out for breakfast since the snails and earthworms were active. Trying to take her picture, I realized the memory card was not in the camera. So I took her for a quick visit to my house, where she could also be weighed. With my son helping balance her upside down on the scale, she registered a whopping 895 grams – about twice the weight of the average adult Box turtle!
But large size alone does not equate to age; I have met younger male turtles almost as big. So how does one recognize advanced age in an animal like a Box turtle that looks old even when it’s young? The image above shows some unique characteristics that most older turtles seem to share. The first is the amount of wear on the carapace and plastron (top and bottom of the shell). The older a wild Box turtle gets (at least the ones I’ve seen that live in forests) the more worn its shell becomes from crawling over and under branches, logs and rocks.
Many people (and I used to be one of them) believe that growth rings on a Boxie’s individual scutes (scales) can be used as an indicator of age, much like tree rings. But turtle scutes apparently don’t make convenient annual growth rings – rather, the rings develop in response to nutrition and other environmental factors. I know this because to fact-check my writing I waded through a very long technical article titled “Estimating Age of Turtles from Growth Rings: A Critical Evaluation of the Technique.”
Another characteristic that seems typical of old boxies is the degradation of the usually crisp, often intricate patterning found on young and middle age turtles. The three older turtles below are unique for the amount of wear and simplification of patterning on their carapace. Two of them also have a wide, upturned rim on the rear of their carapace, as does the female I met yesterday.
Old female turtles unfortunately are rare in this forest, surrounded as it is by roads and mowed parkland. Mowers are particularly dangerous for female boxies, since they often venture out to the sunny forest edges that border meadows and fields to dig their nests. Although nests are regularly plundered and baby turtles eaten by raccoons and other meso-predators, I’m hoping the old female has over her many nesting seasons produced a good number of descendants.
It would be interesting to know how many of the turtles of this forest are related to her. Considering that female Box turtles don’t even reach sexual maturity till they are ten years old, she may still be laying viable eggs. After all, turtles are some of the oldest mothers on earth!