Hibernation for Box Turtles
Most box turtles live in geographic areas that require them to hibernate for three to five months of the year. During this time, food is scarce and outside temperatures are so low that box turtles cannot raise their body temperature high enough to maintain normal activity. Hibernation allows the box turtle to live until better times return in the spring. Hibernation is not a time of cozy sleep, but a dangerous time when bodily functions are barely keeping the box turtle alive. The heart rate slows, digestion stops and the turtle cannot voluntarily move or even open its eyes. Although hibernation is essential for a normal healthy life, many wild and pet box turtles die during this period.
In the wild, box turtles will begin in early fall to search for a protected place to spend the winter. An ideal site may be in the south face of a hill that is easy to dig into and above water level. Or it may be under the sheltering roots of a large tree which are blanketed with fallen leaves or a deep, abandoned rabbit or gopher burrow. It’s unlikely that your outdoor enclosure has an adequate spot for your turtle to hibernate unless you provide some additional materials. It’s also crucial to assess your box turtle’s health before you allow it to hibernate. There are many questions you need to ask and answer before your box turtle can safely hibernate. The first is should you even hibernate the turtle? If it is healthy, then yes. Hibernation helps turtles maintain normal thyroid activity, synchronize their reproduction cycles, and complete their normal life expectancies. These questions should be addressed to an exotics veterinarian along with a medical exam, stool check and in some cases other diagnostics prior to the hibernation period.
Hatchling box turtles that were born just a few months earlier are especially at risk. Many do not survive their first winter. Weak or thin box turtles often don’t have the necessary fat reserves to survive a long winter. Even the healthiest turtle may come out of hibernation too soon and be caught above ground by a spring snowstorm and perish. Many wild box turtles are eaten by foraging animals as they sleep, or freeze to death because they didn’t find satisfactory winter lodgings. You must be aware of all these things. Therefore only hibernate healthy, adult box turtles that have gained weight during the summer. Do not hibernate young, sick or underweight box turtles. Turtles that have worms or have respiratory illness will only get worse in hibernation.
Depending on where you live in the United States, you may need to do more to prepare your outdoor enclosure for hibernating turtles.
In warm states where it rarely goes below freezing the box turtles usually begin to hibernate in November and come out by mid-March or April. Make sure they have areas of soft dirt and leaves to dig into that are above the water table and drains well. In October, begin to mound the dirt and add leaves to the turtle’s enclosure. This is also the time they begin to eat less and rest more. They are preparing their bodies for hibernation. Several times in October, place vitamin A (cod liver oil) onto favorite foods and feed it to them. This will insure they don’t become vitamin A deficient. In the last weeks of October don’t feed them a lot of protein products, mostly dark leafy vegetables, carrots and apples. Once they are in the ground place an old carpet piece over them to add a little more insulation. Make sure there is plenty of fresh water in the pen, in case one comes out for a drink.
In the midwestern or other states that have long, cold winters, make more preparations for the turtle’s hibernation. They must be able to dig into the ground deep enough to hibernate below the freeze line. This level changes during the winter so you need to prepare the ground deeply so the turtle can go down as far as it needs to. Wild turtles have been found hibernating at depths of 2 feet. This area should be protected from drying winds and snow drifts. Some people who live in areas that have very cold and long winters build artificial hibernation dens for their turtles. This is a good way to hibernate your box turtle since it allows you to monitor the temperature and health of your box turtles. This method of hibernation is also recommended for box turtles that live in areas where they are not native.
To build your own hibernation den you will need two boxes, one large and the second one small enough to fit inside the large one, but big enough for the box turtle and some leaves. Fill the large box half way with crumpled newspaper. Fill the smaller box with clean leaves and sphagnum moss. Place your box turtle in the small box after it has already begun to hibernate on its own. Close the box but do not seal it. Put the small box into the larger box and pack the sides and top with more crumpled newspaper. Do not seal the box with tape. Remember, the turtle needs to breathe. Store the boxes in an area that is around 50°F. Be sure the temperature doesn’t fluctuate a lot, but is steady, like an unheated basement, attic or crawl space. An unheated garage may get too cold. Check the temperature of the hibernation area for several weeks before leaving the boxes there. The artificial den should not be set directly on the ground. Use a plastic tarp so ground creatures cannot eat their way into the box. Check up on the turtles weekly. Listen to the box for sounds of the turtle moving around; it may need a drink. If it wakes up too often, the temperature may be too warm or it may be sick. Assess its health and decide if you can continue to hibernate it or if you should bring it out of hibernation and “overwinter” it indoors. If you overwinter it, you must bring its core body temperature up slowly over the course of a week and begin to feed it regularly and keep it warm with summer-like temperatures. Overwintered box turtles should not be kept at suboptimum temperatures and allowed to remain sluggish. This causes them to use too much of their energy reserves and they will become weaker.
If you are going to hibernate a box turtle you’ve kept inside all year, be sure to stop feeding it two weeks before you place it in the box. During the two weeks you must also slowly reduce the temperature inside its living quarters by 5 degree increments so its body has a chance to acclimate to hibernation temperature. Once it becomes sedentary you may place it into the hibernation box.
Here are more do’s and don’ts for successful hibernation:
- Do take the time to prepare a proper hibernation place for your outdoor box turtle. Don’t leave it up to chance.
- Do choose an area that does not flood or collect run off water. Your turtles could drown.
- Don’t hibernate sick, light weight or young box turtles. Keep them indoors in a roomy, well heated tank and feed them all winter long.
- Do protect your hibernating box turtles from foraging wild animals like rats, mice or raccoons and from other pets that may break open their hibernation boxes or dens.
- Do check on your hibernating turtles once in awhile. You may find ill turtles above ground or the signs of wild animals foraging for food.
- Don’t let your turtles hibernate in wet or soggy ground.