As winter settles in across Indiana, many animals are preparing for one of nature’s most remarkable survival strategies: hibernation. While we often picture bears snoozing through the snow, true hibernation looks a little different, and in Indiana, it’s more common among smaller mammals and reptiles than large ones. Hibernation allows animals to conserve energy during the cold months when food is scarce and temperatures drop.
True hibernators, like groundhogs, bats, and some species of mice, experience dramatic changes in their bodies. Their heart rates slow, body temperatures drop, and breathing becomes shallow and infrequent. Bats, for example, may take only a few breaths per minute while hibernating in caves, barns, or hollow trees. This deep state of rest helps them survive months without insects to eat, but it also means they are especially vulnerable to disturbances during winter.
Other Indiana animals enter a lighter state called torpor or brumation. Reptiles and amphibians, such as turtles, snakes, frogs, and salamanders, don’t hibernate in the same way mammals do. Instead, they brumate, settling into mud, leaf litter, or underground spaces where temperatures stay more stable. They remain mostly inactive but may occasionally move during warmer winter days. Mammals like raccoons, skunks, and squirrels also use torpor, waking periodically to eat stored food or take advantage of mild weather.
Even in the quiet of winter, the landscape is far from lifeless. Tracks in the snow, holes in the ground, and subtle movement beneath logs and leaves all tell the story of animals adapting to Indiana’s seasons. As volunteers, being mindful of where animals may be resting, especially bats and reptiles, helps ensure we’re protecting wildlife during one of the most vulnerable times of the year. Winter may seem still, but just beneath the surface, life is waiting patiently for spring.