Student Article
Hibernation: How Animals Sleep Through the Heat and Cold
Metabolism (noun): The process by which the body uses energy.
Dormancy (noun): A period of inactivity or a sleep-like state.
Adaptation (noun): A change in an animal's body or behavior to survive.
Scarce (adjective): Hard to find; rare.
Denning (noun): A lighter form of hibernation used by bears.
What if you could sleep through winter or nap away the hottest days of summer? Some animals do just that to survive harsh weather conditions.
Hibernation: how animals sleep through the cold and heat
Hibernation is a deep sleep that animals use to survive the winter. Their metabolism slows down, their body temperature drops, and their breathing and heart rate slow. This allows them to use less energy. Hedgehogs, bats, and even some frogs hibernate by curling up in cozy nests and burrows, or under muddy ponds.
Hot weather sleep: aestivation
In hot climates, some animals enter a similar state called aestivation. To escape the heat and dryness, snails, lungfish, and reptiles hide in cool, shaded areas or burrow underground. Their metabolism slows, helping them survive until wetter weather returns.
Torpor: brief energy breaks
Torpor is like a power nap for animals. It only lasts a few hours or a day, but it helps them save energy. Birds like hummingbirds and mammals like bats enter torpor when the temperature drops.
Denning: light sleep for bears
Bears have a unique form of dormancy called denning. During winter, they enter a light sleep but can still wake up if needed. Mother bears even give birth while denning. Unlike true hibernators, bears maintain a higher body temperature and can be easily roused.
How do animals prepare to hibernate?
Animals use these strategies to survive tough conditions. Before they hibernate or aestivate, they eat extra food to store fat. This fat gives them the energy they need while they sleep through the harsh season.
The risks of hibernation
Hibernation comes with risks. If an animal wakes too early, it may burn through its fat reserves before food is available. Predators can also attack hibernating animals. Worse, with climate change causing warmer winters, some animals are waking earlier than usual, which can be dangerous.
Fun fact!
The North American common poorwill is the only bird known to hibernate! It hides among rocks and reduces its oxygen intake by 90%, with its body temperature dropping to around 41°F (5°C).
© Dominic Couzens / Our Media
Metabolism (noun): The process by which the body uses energy.
Dormancy (noun): A period of inactivity or a sleep-like state.
Adaptation (noun): A change in an animal's body or behavior to survive.
Scarce (adjective): Hard to find; rare.
Denning (noun): A lighter form of hibernation used by bears.