Turtles “spring forward” too!

You’ve probably noticed that spring has been starting to show up in Georgia. Trees and flowers are blooming, birds are singing, box turtles are basking in the sunlight … wait, box turtles are basking in the sunlight? You know that trees become dormant in the winter, and birds fly south to find warmer temperatures, but have you ever wondered what box turtles do during our Georgia winters? Well, today you’ll learn!

As many of you probably already know, turtles are reptiles, and reptiles are endothermic animals. “Endothermic” is just a fancy way of saying that these animals receive the heat they need for energy from their environment, rather than by making the heat on their own like mammals and birds do. Because of this, reptiles are much more sensitive to changes in environmental temperatures than other animals are.

So, as temperatures begin to cool off in the fall, box turtles begin to “slow down” and become less active because they are not able to create as much energy with the cooler temperatures as they are during the warm summer months. As fall turns into winter, box turtles will actually enter a state of dormancy, or “torpor,” and become completely inactive altogether. Basically, they go to sleep.

Now at this point, you’re probably thinking of a large furry mammal that is well-known for sleeping, or hibernating, through the winter … bears! Bears, and many other smaller mammals, will overeat and pack on the pounds during the late summer and the fall and then their bodies will utilize all of that excess fat as they hibernate during the winter, cozy in their dens or tree cavities. Turtles, while they also become inactive and sleep during the winter months like bears, are slightly different.

You see, turtles don’t hibernate. They brumate. Brumation is a process that is similar to hibernation in that they both involve animals being inactive during the winter months, but these processes differ in that hibernation requires the animal to pack on extra fat prior to going to sleep, and brumation does not. Also, unlike many animals that hibernate, box turtles will actually dig down into the ground for the winter, and will continue to dig deeper as fall turns to winter and temperatures continue to drop.

If you’ve visited the zoo during the colder months, you may have noticed that our outdoor eastern box turtle habitat in front of the Georgia eXtremes building appears to be empty. However, it is not! The eastern box turtles are still there, but they are a few feet underground at this point in the year. Here at Zoo Atlanta, we actually allow many of our box turtles to overwinter outdoors and brumate just as they would in the wild. Why don’t we bring them inside for the winter like we do with some of our other species of turtles and tortoises, you ask? Well, because brumation is actually a very important part of a box turtle’s yearly cycle. It helps its body to cycle naturally, and, in fact, coming out of brumation is what signals to the box turtle that spring has sprung, and that it is time to look for a mate.

As Georgia continues to warm up over the next few weeks, be sure to keep an eye on our eastern box turtle habitat when you visit the Zoo! You just might be lucky enough to be the first one to welcome our box turtles to spring!
Sara Porter
Keeper I, Herpetology