Have you ever wondered why there are birds and mammals at the north pole but not reptiles? Well, reptiles are ectothermic or cold-blooded animals. This physiology makes it difficult to exist at temperatures that are too cold. But, as we know, reptiles are incredible animals and many of them can tolerate the cold.
So, what reptiles can live in cold climates?
Through techniques like brumation, group hibernation, and literally freezing themselves, some reptiles can live in cold climates. Most reptiles don’t do well in the cold, but species like painted turtles, garter snakes, and pygmy short-horned lizards, have evolved to withstand cold weather. Many species of amphibians have also adapted to live in cold climates. Â
In this article, we will talk about the techniques that reptiles use to survive in cold weather. Then, we’ll highlight some of the reptiles that live in cold weather and talk about how they survive the winters. We’ll also mention some of the amazing amphibians that live in cold climates.
First, we’ll talk about why it’s surprising that any reptiles at all can withstand the cold.
Do Any Reptiles Live In Cold Environments?
Reptiles are ectothermic animals. As opposed to mammals which are endotherms, reptiles have to rely on external sources of heat to stay warm. That means that in order to complete metabolic activities, reptiles need to keep their body temperatures at a reasonable level.
It’s one of the reasons why there aren’t many reptiles that don’t need supplemental heat in captivity. For this reason, most reptiles are distributed through tropical and temperate regions in the world. For a reptile, it’s a lot easier to warm up when the weather isn’t too extreme.
Despite this, there are many examples of reptiles that live in cold environments. There are even reptiles that live in areas where it freezes over every winter. It’s hard to imagine a cold, blooded animal being able to survive a harsh winter. Luckily, the reptiles on our list today all have special adaptations that help them deal with freezing temperatures.
How Do Reptiles Survive The Cold?
Each species of cold-weather reptile has its own special method of surviving. However, there are a few main techniques that reptiles use to survive the cold months.
Brumation
Brumation is the hibernation of the cold-blooded world. Brumation occurs as temperatures drop seasonally for many reptiles. Reptiles will dig burrow into dens to stay warm and protected during winter.
Brumation is different from hibernation because ectotherms don’t go into a deep sleep. Instead, they’re actually able to move around to get water and food on warmer days while still being able to go back into brumation.
During brumation, a reptile’s heart rate, respiratory rate, temperature, and metabolic rate will plummet allowing them to stay safe and hidden away from the elements.
Group Hibernation
Group hibernation is another technique that reptiles use to stay warm in cold climates. Snakes, in particular, are fond of group hibernation.
Snake hibernaculum are underground dens, where multitudes of snakes spend their winters. Snake hibernaculum keeps large groups of snakes warm and protected. The body heat of multiple animals alone helps to keep the hibernacula warm and above freezing.
Some people who like and study snakes actually look for these hibernacula during the winter. It’s a great way to see large groups of snakes at once, and sometimes multiple species of snakes will hibernate in one chamber together.
Freezing Themselves
The most extreme technique that reptiles use to live in cold climates is allowing themselves to freeze over.
You heard me right, these reptiles actually freeze!
Will get into species-specific details below, but some reptiles allow their entire bodies to freeze over during the winter. Every metabolic process in their body stops, including their hearts! The only thing that continues is a small amount of brain function.
As spring approaches, these frozen reptiles are able to thaw out and continue on as before.
6 Reptiles That Can Live In Cold Climates
Now that we’ve got a good understanding of what reptiles can do to live in the cold, let’s talk about some of the amazing species that can survive harsh winters all on their own.
1. Painted Turtles
Painted turtles might be the most amazing example of reptiles that can live in cold climates. Adult painted turtles can survive for up to 100 days without food or oxygen.
This is an adaptation for living in ponds where the entire surface freezes over in the winter. Painted turtles can do this by changing their blood chemistry. They basically take materials from their skeleton and shell to break down the lactic acid that builds up while using glycogen to survive the winter.
Actually, painted turtles are even more amazing because they can spend days literally frozen. If turtles hatch as their environment starts to freeze, they can survive four days in a frozen state. Their metabolic processes come to a complete stop.
As they thaw, turtles’ organ systems come back online and they can continue on to be one of the first species that is active again in the spring. Watch the video above for an amazing representation of this process.
2. Garter Snakes
Garter snakes are a common cold-weather reptile species. These snakes brumate every winter when temperatures drop below 60°F.
Garter snakes will spend the entire winter below the frost line underground. As the cold permeates deeper they’ll just move further and further underground. During brumation, these snakes slow down their heart rate, respiratory rate, and overall metabolic rate.
Interestingly, when garter snakes emerge from brumation as temperatures warm, male garter snakes will swarm female garter snakes to form a large snake ball. Sometimes, male garter snakes will impersonate female garter snakes just so they can get the heat from the bodies of other males that are attracted to them.
3. Pygmy Short-Horned Lizards
Pygmy short-horned lizards are another cold-tolerant reptile that lets themselves freeze over in the winter. These spiny lizards are native to the northwestern United States and Canadian border.
These reptiles are able to survive a great range of temperatures growing from hot summers to frozen winters. They have a special behavior that allows them to survive, cold weather. These lizards will dig themselves under the sand to a very specific point. They’ll basically burrow to the point where they’re frozen, but not beyond the point of returning in the spring.
4. Fox Snakes
Fox sinks are another species of snake to reside in the northern part of the United States and can live in cold climates. Because of their native habitat, the snakes are adept at brumation.
These snakes will burrow underground during the cold and freezing months to stay warm, and safe. During this time, they don’t need to eat because their metabolism has slowed. However, if they feel a change in temperature, they might emerge to bask in the sun for a day or two.
5. Rubber Boas
Rubber boas are a species of snake that can tolerate very cold weather. These snakes are found in the wild but are commonly kept in captivity. Unlike many of the other snakes on our list today, rubber boas have an even more remarkable technique for surviving the cold.
Rubber boas have the ability to maintain a higher body temperature around their head, compared to the rest of their body. Helps to protect and preserve their brain function during the cold winters. The coldest-ever body temperature for a northern rubber boa recorded was less than 44°F.
That body temperature was recorded for a live snake. As a reference, remember that the human body temperature needs to be somewhere around 98.6°F. If this temperature varies by just a few degrees we are in big trouble, so it’s amazing that snakes can withstand this amount of fluctuation in internal temperature.
6. Mandarin Rat Snakes
Mandarin rat snakes are notoriously hard snakes to keep in captivity because they like it cooler than most other snakes do. Mandarin rat snakes are endemic to countries like Vietnam, Taiwan, and China, where winters can get very cold.
These snakes survive in the forest by brumating as many other snake species do. The interesting thing about the snakes is that instead of being kept at around 70°F they prefer the cold end of their enclosure to be kept around 60°F.
It’s safe to say that Mandarin rat snakes thrive in cold climates.
2 Amphibians That Can Live In Cold Climates
This article will not be complete without a few honorable mentions of amphibians that can live in cold climates.
1. Wood Frogs
Unlike other frogs and toads that burrow to stay warm, would frogs stay warm, with a totally different physiological process. In a bazaar method of survival, these frogs are frozen alive and use their urine to get them through months of cold weather.
Essentially, wood frogs produce their own antifreeze that keeps them alive and their cells functional even though the outside of their body is frozen.
It’s a little hard to explain, but the video below does a great job and you can watch a frog thought out right in front of your eyes.
It’s important to know that there are many other frog species that can live in cold climates. Unfortunately, we need days of your time to go over all of them. Wood frogs just happen to be one of the best-studied and most spectacular species.
2. Siberian Salamanders
Out of all the animals we’ve discussed today Siberian salamanders are the most tolerant of cold climates.
These animals use glycogen as a cryoprotectant when temperatures drop. Incredibly, Siberian salamanders can survive their body temperature dropping down to about -67°C, and they can survive their bodies remaining around -30°C for over a month at a time.
Somehow, this process doesn’t seem to harm their bodies but rather makes them longer-lived amphibians overall.
Final Thoughts
It’s amazing to think that cold-blooded, finicky reptiles can survive some of the coldest temperatures on Earth. Sometimes a difference of just a few degrees can upset our captive reptiles. However, in the wild, some reptiles spent days at a time literally frozen solid.
Reptiles that can live in cold climates have special adaptations that allow them to survive harsh winters. Hopefully, you’ve learned a thing or two from this article and have a new appreciation for your reptilian and amphibian friends.
