Snakes are cold-blooded reptiles that rely on external heat sources to regulate their body temperature. This means that in the winter when temperatures drop, snakes begin exhibiting behaviors to deal with the cold weather. Generally speaking, snakes will migrate to suitable overwintering sites, brumate underground, or find other ways to escape the frigid conditions.
Do snakes hibernate in the winter?
Many people wonder if snakes “hibernate” in the winter like some mammals do. While snakes do exhibit dormancy behaviors in winter, they do not truly hibernate. The proper term for a snake’s winter dormancy is brumation.
Brumation differs from hibernation in that it is not a true deep sleep. Snakes that brumate can still be alerted by stimuli and do not exhibit the dramatically lowered body temperatures seen in hibernating mammals.
Where do snakes go in winter?
Snakes utilize a variety of winter retreats to escape the cold and find shelter while brumating. Common overwintering sites include:
- Underground burrows or crevices between rocks
- Hollow logs, stumps, or abandoned animal burrows
- Leaf litter or underground shelters
- Man-made spaces like woodpiles, crawlspaces, or foundations
Aquatic snakes like water snakes may brumate underwater. Tree-dwelling snakes find hollows in tree trunks or limbs.
Do all snakes brumate?
The vast majority of snake species living in temperate climates will brumate over winter. However, some exceptions include:
- Rattlesnakes – May remain active through warmer winters
- Garter snakes – Sometimes brumate in communal dens with other snakes
- Water snakes – Brumate underwater
- Tree snakes – Wedge into hollow tree trunks
Tropical snakes living in consistently warm climates do not need to brumate at all.
When do snakes begin brumation?
Snakes begin retreating to their overwintering sites in late fall or early winter. The exact timing depends on factors like:
- Species – Some enter brumation earlier than others
- Geography – Colder climates see earlier brumation
- Age – Younger snakes may brumate longer than older, larger ones
- Health – Well-fed snakes brumate longer
- Weather – Early cold snaps or warm spells affect timing
In places with very cold winters, snakes may enter brumation dens as early as late September. In more mild climates, snakes may stay active into late fall before settling into brumation.
How long do snakes brumate for?
The brumation period lasts through the entire winter for most snakes. Brumation may last:
- 4-6 months for snakes in cold northern regions
- 2-3 months for snakes in warmer southern climates
- 5-7 months for juveniles and hatchlings
Snakes emerge from brumation when temperatures warm in early spring. The exact timing depends on the species and local conditions.
Do snakes eat during brumation?
Snakes do not eat while brumating, since digestion requires more energy than is ideal. However, some snakes may occasionally drink water if the opportunity arises:
- Younger snakes are more prone to drinking
- Milder brumation conditions may allow for occasional drinking
- Very cold or dry brumation sites prohibit drinking
Snakes living off stored fat reserves burn fewer calories if water intake is limited, so drinking is minimized.
What happens to snakes in brumation?
During brumation, snakes exhibit the following characteristics and behaviors:
- Greatly slowed metabolism
- Lower body temperature – Near ambient temperature
- Minimal activity or movement
- No eating
- Seek sheltered overwintering sites
- Altered breathing patterns
Despite appearances, brumating snakes are not dead. They remain somewhat alert and can move if disturbed or temperatures rise.
Do snakes die in winter?
Healthy snakes are well-adapted to survive winter through proper brumation. However, occasional deaths can occur due to:
- Extreme cold – Temperatures below a snake’s tolerances
- Lack of suitable sites – Nowhere to escape the cold
- Starvation – Inadequate fat stores to live off
- Dehydration – Lack of any water intake
- Predation – Brumating snakes are vulnerable
Death rates are higher in exceptionally frigid winters. Small, young, or underweight snakes are also at higher risk.
How do snakes survive winter?
Snakes survive winters through anatomical, physiological, and behavioral adaptations that allow successful brumation:
- Fat stores – Building up reserves before winter provides energy
- Lower metabolism – Greatly slowing metabolism requires less energy
- Altered breathing – Specialized lungs allow long breath-holding
- Sheltered sites – Insulated hibernacula prevent freezing
- Communal dens – Shared sites offer warmth benefits
Together these adaptations allow snakes to persist through harsh conditions in winter.
Do snakes come back after winter?
In most cases, snakes return to normal activity after emerging from brumation in spring. Things that influence post-brumation recovery and survival include:
- Available food – Starving snakes may struggle to find meals
- Water – Rehydration is crucial after winter
- Basking sites – Access to sun and heat allows temperature regulation
- Suitable habitat – Shelter and hiding spots help avoid predation
- Energy reserves – Snakes rely on remaining fat stores until eating
With proper habitats and resources, most snakes recover fully from brumation within a few weeks of emergence.
Do snakes relocate dens before winter?
Some snake species like rat snakes and rattlesnakes do exhibit seasonal migration or translocation to reach suitable brumation dens. Factors prompting this include:
- Lack of adequate sites near summer range
- Following scent trails to traditional dens
- Hardwired instinct to move to ancestral dens
- Regional weather changes
- Availability of prey nearby dens
Not all snakes migrate far, but those that do begin moving in late summer or fall to reach winter sites.
How far do snakes travel to brumate?
Migration distances to reach winter brumation dens vary greatly by species and local conditions. Some examples include:
- Timber rattlesnakes – Up to 4 miles
- Copperheads – 300-600 yards
- Rat snakes – Up to 2 miles
- Garter snakes – Up to 0.6 miles
- Water snakes – 50-100 yards if not aquatic dens
Snakes may remember and reuse the same winter dens annually, generation after generation.
Can snakes freeze to death?
Snakes can withstand much colder temperatures than humans, but they can still freeze to death in certain conditions:
- Temperatures below -4°F may cause freezing
- Direct contact with ice or snow increases risk
- Smaller snakes freeze faster than larger snakes
- Poor body condition or starvation make snakes vulnerable
- Exposed areas without shelter are dangerous
To avoid freezing, snakes seek insulated underground shelters or “supercool” by removing ice nucleators from their blood.
Do snakes hibernate together?
Some gregarious snake species exhibit communal brumation in shared winter dens. Benefits include:
- Shared body heat can raise temperatures
- Group sites are easier to find
- More eyes watch for predators
- Social structure is maintained
Examples of snakes known to brumate communally include garter snakes, copperheads, and timber rattlesnakes. Not all dens house huge numbers, but even a few together can aid survival.
Conclusion
Snakes employ fascinating behavioral and physiological adaptations to survive harsh winters through brumation. By retreating underground, lowering metabolism, and tolerance of colder temperatures, snakes are well-equipped to wait out the winter season until conditions become favorable again in spring.