Where have all the turtles gone?
It’s that time of year again! The time of year that some of the outdoor habitats for turtles and tortoises have signs on them saying that the Georgia temperatures can get too chilly for that species. In fall and spring, I often overhear guests commenting “But it’s a beautiful 76-degree day! How is that too cold?” And they are absolutely right! 76 degrees and sunny are great conditions for turtles and tortoises to be outside in. However, this time of year, while it may be warm during the day, it frequently drops into the 40s and 50s overnight, which is too cold for many turtle and tortoise species.
So, because of this, we move most of our turtles and tortoises inside for the winter, usually beginning in late September or early October depending on the forecast. We have many turtles and tortoises here at Zoo Atlanta, so moving them all is quite the undertaking that the whole Herpetology Team will help with!
Similar to what the Bird Department does to prep for winter (see their recent Keeper Story on “winterizing”), we also are quite busy in the Herpetology Department getting the winter housing areas ready for the turtles and tortoises. This involves bleaching floors, mulching habitats, setting up heat lamps and basking areas, and gathering “furniture” for the animals’ new winter digs, such as logs, rocks, branches, leaves and hides. If you’ve been to Zoo Atlanta in the fall, you’ve probably seen a member of the Herpetology Team raking leaves, and now you know why!
However, not all of our animals move indoors during the winter. A few of our turtle species will remain outdoors year-round, to allow them the opportunity to “brumate,” which is the reptile version of hibernation. Even though they will stay outside during the colder months, there is still a bit of prep we as keepers have to do for them to make sure that they are safe and comfortable despite the cooler temperatures.
The first thing we do is break up the ground in the area they’ll be staying in. The looser substrate allows them to burrow into the ground easily, which is critical to their brumation. The next thing we do is, you guessed it, gather leaves! After we’ve gathered enough leaves, we add a big pile of leaves to each space, so that they have that extra layer of insulation while they are underground. For native species, such as eastern box turtles, that’s all we have to do! Pretty simple, right?
For non-native species that will be overwintering outdoors, we will either add lots of leaves to their pond, so that they have a warm leaf layer to nestle down into, or we will add lots of leaves in and around their hibernaculum, as well as further insulate the hibernaculum with a layer of hay on the outside. “Hibernaculum” is the term for the structure where a hibernating (or brumating) animal spends the winter. In the wild, this could be things like caves, rock overhangs, or hollows in trees. At Zoo Atlanta, we have small man-made structures similar to caves that we use as hibernacula for our Mexican box turtles and our McCord’s box turtles.
Now you know where all the turtles have gone! Rest assured, they’ll all be back and ready to see you next year!
Keeper I, Herpetology