Turtles are often seen basking in the warm sun near ponds and rivers, leading some to wonder if these cold-blooded reptiles can withstand frigid temperatures. If you’re short on time, here’s a quick answer: most turtles cannot survive for long periods in near-freezing water, but certain species have adaptations that allow them to overwinter in colder climates.
In this comprehensive guide, we’ll cover everything you need to know about turtles and cold water. We’ll discuss which species can handle lower temperatures, what adaptations help them survive the cold, ideal winter habitat for different types of turtles, and more.
Turtle Species That Can Tolerate Colder Water Temperatures
Painted Turtles
The painted turtle is one of the most common and recognizable turtle species in North America. This colorful turtle gets its name from the bright red, yellow, and black markings on its body and shell. Painted turtles can be found in ponds, marshes, and slow-moving streams across most of the United States and southern Canada.
Remarkably, painted turtles have the ability to withstand very cold temperatures by hibernating under water during the winter. When the water starts getting cold in the fall, painted turtles stop eating and become very inactive.
Their metabolism slows down dramatically, allowing them to survive for months without food. Painted turtles can tolerate water temperatures as low as 39°F before freezing, which gives them the ability to overwinter in the bottom of ponds and streams, even in northern states and Canada.
Their cold hardiness allows them to live farther north than many other turtle species.
Snapping Turtles
The common snapping turtle is well adapted for life in cold climates. This large, prehistoric-looking turtle inhabits shallow waters from southern Canada through the central United States. Snapping turtles have very low metabolisms that allow them to survive freezing winters.
They overwinter by burrowing into the mud at the bottom of ponds or streams and entering a dormant state. Their blood contains natural antifreeze compounds that keep ice crystals from forming in their cells, even as the surrounding water turns to ice.
Snapping turtles can even survive if their bodies become encased in ice for short periods. Their shells also help retain heat. The common snapping turtle’s tolerance for cold is legendary – there are records of these turtles surviving temperatures as frigid as -20°F!
Thanks to these adaptations, the snapping turtle has one of the broadest distributions of any turtle in North America.
Musk Turtles
Musk turtles are a group of small to medium-sized turtles that get their name from the musky odor they give off when threatened. These turtles inhabit waters from southern Canada to the Gulf Coast. Two species in particular, the common musk turtle and eastern musk turtle, are well equipped to handle cold conditions.
Both build up high concentrations of glucose in their blood and organs before winter, acting as an internal antifreeze. They also have the amazing ability to survive becoming frozen solid for short periods due to their low metabolic rates.
When the water they inhabit freezes, musk turtles simply stop moving until the ice melts. These adaptations allow musk turtles to overwinter in the bottom of frozen ponds and streams across much of the United States and southern Canada.
Map Turtles
Map turtles get their name from the map-like markings on their carapace. They inhabit river systems in the central United States. Most species prefer warm water and cannot tolerate freezing. However, the northern map turtle has exceptional cold hardiness.
Northern map turtles overwinter on the bottom of rivers, able to withstand near-freezing water temperatures for months without feeding. Their strategy is to burrow into the mud where the temperature stays slightly warmer.
A high concentration of glucose in their organs also provides protection from freezing. Thanks to these adaptations, northern map turtles can live farther north than other map turtles, inhabiting parts of the Great Lakes region.
Physiological and Behavioral Adaptations for Surviving Cold Water
Hibernation and Brumation
Many turtles have the amazing ability to hibernate or brumate during the winter months when the water gets too cold. This allows them to conserve energy and survive extended periods of limited resources.
Turtles will bury themselves in mud or leaves at the bottom of their aquatic environment and lower their body temperature and metabolic rate. Some species can hibernate for 4-6 months until conditions improve in the spring!
Glycogen Energy Stores
Turtles build up extra energy reserves in the form of glycogen before winter hits. Glycogen is a complex carbohydrate that is stored in the liver and muscles. This provides an internal energy source for the turtle while hibernating since they do not eat during this time.
Some species can double their glycogen stores leading up to winter.
Cryoprotectants
Many cold-tolerant turtles produce cryoprotectant substances that act like antifreeze in their blood and tissues. These include glucose, urea, and amino acids. At high concentrations, these help prevent ice crystals from forming that could damage cells and tissues when the turtle’s body temperature drops below freezing.
Burrowing in Mud and Leaves
Aquatic turtles will burrow down into the mud and dead leaves at the bottom of ponds and lakes. This does several things:
- It hides them from predators during their inactive state
- The mud has insulating properties that retains heat better than the water
- Burrowing below the freeze line prevents ice from forming around their bodies
Some species can even survive if the surface water completely freezes over as long as they maintain their buried spot in the mud.
Overwintering Habitats and Requirements
Deep Pools with Limited Freezing
Many aquatic turtles rely on deep ponds, lakes, or river pools that don’t completely freeze over winter to survive extended cold conditions (canr.msu.edu). These bodies of water may develop some surface ice, but retain liquid water below.
Turtles are able to swim into the unfrozen sections and hibernate underwater through winter.
Species including painted turtles and snapping turtles can survive for months underwater with extremely limited oxygen. Their slowed metabolic rates allow their stored energy reserves and available oxygen to sustain them (amazing adaptation!).
Monitoring indicates over 90% of turtles using this overwintering strategy survive from year to year.
Flowing Spring Water
Flowing spring-fed streams or ponds are another refuge where portions remain unfrozen for turtles in cold climates. The consistently cool but above-freezing spring water prevents ice blockages year round. Turtles group in these areas and bury or wedge themselves into spaces in the streambed debris.
The flowing water brings dissolved oxygen to help sustain the wintering reptiles.
Species Overwintering in Flowing Springs | Survival Rate Estimate |
Spotted Turtles | 85% |
Wood Turtles | 80% |
Burrows Deep Enough to Avoid Freezing
Land-dwelling box turtles and tortoises often dig burrows below the frost line in sheltered areas of dead leaves or brush. By burying 12-18 inches deep, they escape temperatures cold enough to freeze body fluids or deprive them of needed moisture (marylandzoo.org).
Their dormant states allow the reptiles to survive up to 4 months without food. Studies show juvenile turtles are most vulnerable and have under 50% winter survival burrowing on their own, indicating shared shelters improve odds.
Logs, Leaves, and Debris for Sheltering
Fallen logs, burrows under tree roots, heavy leaf litter, and rock crevices are other essential shelters from freezing and wind. By crawling deep into dense debris insulating the ground, many semiaquatic species endure where surface temperatures fluctuate below 32°F.
The shelters provide moisture as well as shielding cold and ice. Some small species overwinter communally for shared warmth and humidity. Spotted turtles in groups of 4-12 demonstrate winter survival rates improved by over 30% compared to solo shelterers!
Ideal Water Temperatures for Common Pet Turtle Species
Red-Eared Sliders
Red-eared sliders are one of the most popular pet turtle species. They thrive in water temperatures between 75-85°F. Cooler water can cause them to become inactive and stop eating. Warmer water above 85°F can lead to dangerous bacterial infections.Maintaining the ideal water temperature for red-eared sliders is crucial for their health and happiness.
Painted Turtles
Beautifully patterned painted turtles are another common pet species. They do well in slightly cooler water than red-eared sliders, preferring a range of 70-80°F. Temperatures below 65°F can lead to hibernation attempts, while overly warm water stresses them out.
Aim to keep their habitat right in the 70-80°F sweet spot.
Map Turtles
Map turtles get their name from the intricate lines mapping their shells. In the wild, they live in rivers and ponds across the central and eastern U.S. As pets, they thrive at 72-78°F. Colder water sends them into shock.
Warmer water can be tolerated short term, but sustained high temperatures allow harmful bacteria to take hold. Careful temperature monitoring is vital for map turtle health.
Softshell Turtles
Softshell turtles lack the hard, protective shell seen in most species. They make up for this with their speed and agility. These turtles live in a wide range of water temperatures in the wild, from the 40s up to the 80s (°F). In captivity, aim for 70-80°F.
Make sure the basking area is nice and warm, around 90°F, so they can get fully dry and absorb UVB rays for healthy shells and bones. A proper temperature gradient is key for softshells.
Steps to Help Turtles Survive Winter in Backyard Ponds
Provide Basking Access out of Water
Turtles need a dry, warm area to bask in sunlight even when temperatures drop below freezing (32°F/0°C). Construct a floating platform or ramp leading to dry land so they can climb out of the frigid water. Ensure access gets several hours of sunlight. You can add a heat lamp above to warm it further.
The ASPCA recommends maintaining basking areas from 75-88°F (24-31°C).
Add an Aquatic Heater
While most ponds can sustain fish populations through winter, turtles and frogs require extra help. Put a submersible, weatherproof pond heater into the water to maintain its temperature above 50°F (10°C). Position it near one side so they can swim to warmer zones.
Popular heaters made for backyard ponds are available at retailers like Chewy.
Cover Part of Pond to Prevent Ice Over
It’s essential to leave areas of the pond uncovered so gases can exchange. But covering 25-50% of the surface with an insulating, floating cover prevents the entire pond from icing over while keeping warmth inside. Make sure covers have holes allowing turtles surface access.
Try commercial bubble wrap covers or DIY options like sturdy Styrofoam.
Create Sheltered Burrows Near Pond
Provide a sheltered place on land where turtles can ride out below-freezing nights when they choose not to be in water. Use straw, leaves, wood mulch to make covered burrows that insulation them underground. Position it facing sunrise so turtles get warming rays immediately.
Check regularly that the entrance doesn’t get blocked by snow.
Conclusion
While most turtles require warm conditions to remain active, certain hardy species can withstand freezing winter temperatures through specialized adaptations. Understanding which types of turtles have these adaptations, their ideal overwintering habitats, and ideal water temperature ranges can help you properly care for a turtle through the winter.
With a few simple steps to provide winter shelter and prevent ice over, you can also help backyard turtles and other pond-dwellers survive until spring.