When winter arrives, wildlife faces one universal challenge: how to survive when food is scarce and temperatures drop. While many people assume animals simply “hibernate” through winter, the reality is far more nuanced.
Different species use different survival strategies, and two of the most commonly misunderstood are hibernation and brumation. Though they sound similar, these processes are biologically distinct — and understanding the difference helps explain why some animals disappear in winter while others remain surprisingly active.
Why Winter Forces Wildlife to Adapt
Winter creates harsh conditions for animals:
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Limited food availability
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Cold temperatures that increase energy demands
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Reduced daylight hours
To survive, animals must either store energy, slow their metabolism, or remain active using alternative strategies. Hibernation and brumation are two solutions to the same problem — conserving energy when resources are scarce.
What Is Hibernation?
Hibernation is a deep, prolonged state of dormancy used by certain mammals to survive winter.
During hibernation:
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Body temperature drops dramatically
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Heart rate and breathing slow to a fraction of normal levels
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Metabolism decreases significantly
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The animal does not eat, drink, or remain aware of surroundings
True hibernators rely entirely on stored body fat to survive for weeks or even months.
Common Hibernators
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Groundhogs
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Bats (some species)
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Chipmunks (partial hibernation)
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Certain rodents
These animals retreat to insulated dens, burrows, or caves where temperatures remain relatively stable.
What Is Brumation?
Brumation is a similar but distinct process used by reptiles and amphibians. Because these animals are cold-blooded, their survival strategy works differently.
During brumation:
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Activity slows dramatically
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Metabolism decreases
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Animals remain semi-aware
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They may occasionally wake and move
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Body temperature matches the environment
Unlike hibernating mammals, animals in brumation may emerge briefly during warmer winter days.
Common Animals That Brumate
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Snakes
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Lizards
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Turtles
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Frogs and toads
They typically shelter underground, in rock crevices, mud, or leaf litter where temperatures fluctuate less dramatically.
Why Animals in Brumation May Still Be Seen
Because brumation isn’t a deep, continuous sleep, animals may appear unexpectedly during winter warm spells. This can surprise people who assume reptiles and amphibians “disappear” entirely.
Seeing a snake or turtle on a warm winter day doesn’t necessarily indicate a problem — it’s often a natural response to temporary temperature changes.
Not All Animals Hibernate or Brumate
Many animals remain active throughout winter by using alternative strategies.
These include:
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Growing thicker fur
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Storing food caches
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Changing diets
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Reducing activity levels
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Using sheltered urban environments
Animals like squirrels, raccoons, coyotes, and deer stay active year-round, adjusting behavior rather than shutting down completely.
Urban Environments Change the Rules
Cities create warmer microclimates that can disrupt traditional winter patterns.
Urban wildlife may:
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Shorten dormancy periods
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Remain active longer into winter
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Use buildings and infrastructure for warmth
This is why animals that typically hibernate or brumate may behave differently in urban or suburban areas.
Why Understanding These Differences Matters
Confusing hibernation and brumation can lead to misunderstandings about wildlife behavior.
Understanding the difference helps people:
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Recognize normal seasonal activity
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Avoid unnecessary concern when animals appear in winter
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Better appreciate wildlife adaptation
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Reduce fear-based reactions
Animals are not “out of place” — they are responding to environmental cues.
Final Thoughts
Hibernation and brumation are remarkable examples of nature’s ability to adapt. Though they serve the same purpose — surviving winter — they operate through entirely different biological mechanisms.
Whether an animal sleeps deeply beneath the snow or slows down just enough to endure the cold, these survival tactics reveal the incredible resilience of wildlife. Winter may seem quiet on the surface, but beneath the ground, in dens, burrows, and hidden shelters, life is very much continuing — just at a slower pace.
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Thanks!
-Wildlife x Team International