In their natural environments many box turtles and true tortoises hibernate from October or November until late February, March or even early April. The natural shortening of day length and the reduced brightness of daylight, as well as the decreased availability of food, are among the cues that induce hibernating behavior. The animals burrow deep in leaf litter or soft earth, which insulates them from temperature changes. As the days lengthen and temperatures rise, they emerge in the spring.
For more information, please read the article Your Tortoise or Box Turtle and Hibernation