Bears prepare for hibernation in a few key ways:
- Eating Up: In the fall, bears go into a period of hyperphagia, which means they gorge themselves on food. They're trying to pack on as much fat as possible. This fat will be their main energy source during the long winter months.
- Finding a Den: Bears look for a safe and warm place to spend the winter. This could be a cave, a hollowed-out tree, or even a hole in the ground. They line their den with leaves, twigs, and other materials to make it as comfortable as possible.
Entering Torpor: While it's often called hibernation, a bear's winter sleep is actually a state called torpor. Here's what happens during torpor:
- Slowing Down: The bear's body temperature drops slightly, their heart rate slows down significantly, and their breathing becomes shallow. Their metabolism also slows way down, helping them conserve energy.
- Living off Fat Stores: Since they aren't eating or drinking, bears rely on their fat reserves for energy. Amazingly, they can recycle their waste products into usable nutrients!
- Not Quite Sleeping: Bears aren't completely motionless during torpor. They may wake up occasionally to move around and even give birth (in the case of mother bears).
So, while bears aren't exactly catching a long winter nap, they are in a low-power state that allows them to survive the winter without food or water.
