Just about everyone has heard of hibernation, which is a way that many creatures such as bears, butterflies, and even one bird – the common North American Poorwill – survive the winter by slowing down or in some cases, sleeping deeply until spring arrives.
So, do red-eared sliders hibernate? Well, sort of!
Reptiles do something similar, but their sleep is not as deep, and the activity itself is called brumation. What happens is that the temperature drops and the reptile reduces their metabolic activity in response.
This allows creatures like the red-eared slider to survive harsh winters, as their reduced metabolic activity means that they need less energy, and when it’s warm again they return to ‘normal speed’ and get back to their regular daily activities.
Brumation isn’t limited to just wild sliders, however — pet red-eared sliders also brumate, and this is something that they’ll need to do before breeding. While it performs some useful functions, such as ensuring that pet red-eared sliders burn off excess fat reserves, brumation has its dangers.
There is always the risk that unhealthy or weak individuals may not survive brumation, so let’s talk about it more so that you’ll have the facts that you need to know about this reptile survival trait and what it means for your pet slider!
Table of Contents
Wild Red-Eared Slider Brumation
Among wild red-eared sliders, brumation occurs whenever temperatures are low, generally starting in October when temperatures are starting to fall regularly below 50 degrees Fahrenheit (10 degrees Celsius).
During this time, wild sliders will generally brumate underwater at the bottom of lakes and ponds. Individuals can also be found brumating in hollow stumps, rocks, and under the banks of the water body that they inhabit.
The extent of inactivity during brumation isn’t universal. While some individuals are completely inactive, some individuals are simply LESS active. Some individuals remain in a state of sopor ( a VERY deep sleep) and do not eat or pass waste. They are motionless and their respiration slows down to almost a halt.
Although they remain mostly inactive, sliders do rise to the surface to breathe and feed when necessary, but they need very little in this state. That’s because their metabolic rate is greatly reduced and as a result their their heart rates slow down as well – with cardiac output falling as much as 80%!
During brumation, some turtles can survive for weeks without oxygen and respire anaerobically by producing ATP (Adenosine triphosphate) from glycolysis. The buildup of lactic acid during this state is countered by the minerals in their shell, preventing acidosis.
Acidosis refers to increased acidity in the body and blood., while ATP is a compound that produces energy.
Among wild red-eared sliders, brumation starts around October and typically ends in early March to late April. On warm winter days when the temperature isn’t cold, the turtle may become active and even bask a little in the warm sunlight.
Once temperatures drop below 50 degrees Fahrenheit, the turtle will resume brumation again as needed until it warms up again. Simply put, the temperature of its locale dictates the behavior of the reptile.
While it’s a solid survival trait, brumation is a stressful ordeal for wild freshwater turtles, and unhealthy or otherwise weakened individuals may not survive the winter.
While captive sliders may not need to brumate if you don’t intend to breed them, this activity is conducive to good reproductive and overall health.
Pet Red-Eared Slider Brumation
As mentioned, it isn’t necessary for pet turtles to brumate, considering how risky it is. With that said, sometimes it may be necessary to allow your captive-bred red-eared sliders to brumate if you wish to breed them. This is referred to as a ‘cooling period’.
Cooling your turtles increases the chances of a successful breeding season and this activity occurs from January to February. Here’s a quick run-down of cooling period basics:
- To cool your captive-bred terrapin, drop the temperature of the water and enclosure to 50 to 60 degrees Fahrenheit.
- You can also allow the turtle to cool outside if your turtles live in an outdoor pen/pond. This is much riskier, as the turtles are left to the elements.
- During the cooling period, provide food for the turtle, even though they may not eat or eat little.
- The cooling period should last for about 8 to 12 weeks.
Whether or not you are breeding your red-eared slider, you’re still going to need a nesting box, because the female will lay eggs anyway! Find out how to create a red-eared slider nesting box so that you’ll be ready.
Aquatic Turtle Brumation Process
Freshwater turtles usually brumate when temperatures start to fall and during this time, the reptile will generally eat more to prepare for brumation. Once temperatures drop significantly, the slider will become more lethargic, and will stop feeding — the turtle doesn’t want undigested food in its digestive tract.
That’s because their decreased metabolism means that the turtle won’t defecate, so having the food in its system can be detrimental to its health as it will just sit there and rot, potentially causing a bacterial infection.
The heart rate slows from about 40 beats a minute to around 10 beats a minute and during this time, aquatic turtles remain dormant underwater – a low-oxygen environment. Within there, the turtle uses little to no oxygen and is able to survive without it for several months!
Remaining in a low-oxygen environment means that cellular respiration has to be anaerobic. This produces ATP (Adenosine triphosphate) from glycolysis, but this type of cellular respiration over a long period of time also leads to a buildup of lactic acid.
This is the same type of acid that is produced when humans exercise or perform other strenuous activities — your sore muscles are the result of lactic acid!
Unlike humans, that buildup of lactic acid in turtles is countered by the minerals in their shells, and that’s what prevents acidosis. After 230 million years of evolution, it’s safe to say that turtles have learned a useful trick or two!
Underwater Respiration While Brumating
The red-eared slider is one of the many aquatic turtles that can breathe oxygen underwater. These reptiles are able to respire through their cloaca through a process called ‘cloacal respiration’.
This respiration is limited, however — when active, the organ isn’t effective enough that the turtle doesn’t need to breathe air. When brumating, this respiration is considered a form of ‘cutaneous respiration’, which is just a fancy way of saying it’s respiration associated with the skin.
It’s quite effective, as this survival trait can provide the slider with the oxygen needed to survive underwater.
The way it works is the slider absorbs oxygen by moving water over the cloaca, which has a high concentration of blood vessels. The cloaca is located in the ‘butt’ of the turtle and it uses this organ to expel waste.
By expanding and contracting specialized muscles in the cloaca, the turtle is able to force water in and out of it, and this allows the turtle to absorb oxygen in the water.
For those interested in learning more, PBS News has a fantastic article with a funny title that you can check out — ‘The secret to turtle hibernation: Butt-breathing‘.
Brumation vs Hibernation: Similarities and Differences
Brumation and hibernation are similar and serve a similar purpose – providing a physical state that allows the animal to conserve energy and subsequently, to survive the winter. The difference is down to the type of animal, but in a nutshell, cold-blooded animals brumate, while warm-blooded animals hibernate.
With warm-blooded animals, hibernation functions to conserve energy use when there is a lack of food. Warm-blooded animals decrease their metabolic rate, which in turn decreases their internal body temperatures. With cold-blooded animals, brumation occurs naturally when temperatures fall.
As cold-blooded animals rely mostly on external temperatures to determine their internal body temperature, once the external temperature drops, so does their internal body temperature. This drop in temperature, in turn, drops their metabolic rate.
Brumation involves dormancy with occasional moments of activity, while hibernation involves deep and continual physiological sleep.
A slowdown in metabolic rate and processes occurs during both brumation and hibernation. Reptiles generally brumate in low-oxygen environments such as underwater or in mud, as they are quite capable of surviving in low-oxygen environments.
This adaption is due to the glycogen content in their blood. Mammals, on the other hand, require oxygen saturation to survive.
With hibernation, there usually aren’t moments of punctuated activity — waking up can be fatal, in some cases, as most animals feed heavily in preparation to have the energy to survive the process. With brumation, there are moments of punctuated activities, such as surfacing to breathe or taking an opportunistic snack.
During hibernation, mammals sleep, but reptiles technically do NOT. Instead, they enter into a period of prolonged dormancy that’s essentially just slowing down their bodies. They usually come out of this dormancy when the temperature fluctuates, such as on warm winter days.
During these times, they will typically come out to bask in the sun, and once the temperatures drop again, they return back to brumation until the temperature is conducive for renewed activity again.
Both brumation and hibernation are triggered by changes in the seasons. The shortening of the day and the fall in temperatures usually trigger both states of dormancy, and both reptiles and mammals eat a lot in preparation. This ensures that both build a fat reserve, which they can burn through while dormant.
Mammals do not eat during hibernation, as they are deeply asleep, and most reptiles usually do not eat during brumation, although they are capable if a lucky opportunity arrives and their bodies need the fuel.
Different Between Brumation and Estivation
Another state of dormancy that occurs is estivation, which is also known as ‘aestivation’. Estivation occurs when temperatures are high and the conditions are dry. Brumation occurs when temperatures are simply low.
Turtles are known to estivate when temperatures are very high and during this time, they will generally bury themselves in mud. During estivation, the metabolic rate of the species is lowered, in much the same manner as brumation and hibernation.
Reptiles estivate to avoid desiccation, which is just a fancy way of saying ‘drying up’, and to avoid other risks associated with high temperatures. Thankfully, your red-eared sliders aren’t known to estivate, so you won’t need any special preparation in this regard, but they do brumate if you’re going to breed them.
Now that you know more about the process, you should be better prepared to help your turtles with brumation so that they’ll be at their best physical and reproductive health for breeding healthy and happy hatchlings!
Frequently Asked Questions
Do red-eared sliders hibernate indoors?
They don’t hibernate, but they have a reptilian version of a similar process called ‘brumation’. Red-eared sliders can and do brumate indoors, whenever the temperatures are low enough.
This is a survival trait in reptiles that helps them to survive the winter and while it’s dangerous, it’s also actually good for their physical and reproductive health, and you’ll need to encourage brumation if you intend to breed your sliders.
Do red-eared sliders brumate in captivity?
Yes, the red-eared slider’s period of dormancy during winter is called brumation and they do brumate indoors when the temperatures are low enough. When kept in an outdoor pond, they will naturally brumate when the winter arrives.
How long do red-eared sliders hibernate?
Red-eared sliders can brumate (the reptilian process similar to hibernation) for 2 to 5 months. The duration will be dictated by the temperature, and when it fluctuates, sliders take a ‘break’ from brumation to bask in the sun and sometimes to grab a quick snack.
If the temperature drops again, they go back into brumation and await the next temperature change before they resume activity.
Is my red-eared slider brumating or dead?
The only way to check whether your turtle is brumating or dead is to pick it up. Dead turtles are limp and their limbs swing easily. Brumating turtles, however, will respond to you handle them and their limbs will not sway or swing easily.
They will be a bit sluggish as their metabolisms have slowed down, but they will definitely respond.
How long can red-eared sliders live in cold water?
While brumating, red-eared sliders can live in cold water for 2 – 5 months. Red-eared sliders should only be in cold water, however, while brumating, as this is a process that naturally occurs during winter. During this time, the turtle enters a state of dormancy and reduces its metabolism as a survival adaption.
If the slider isn’t brumating, it shouldn’t be in cold water – the temperature of the water should be around 75 degrees Fahrenheit.
Conclusion
Red-eared sliders do NOT hibernate, because cold-blooded animals have their own process called ‘brumation’. While these two activities are similar, there are a few differences, with the biggest difference being that during hibernation, mammals sleep, but reptiles do NOT.
While red-eared sliders don’t technically hibernate, the terms ‘brumate’ and ‘hibernate’ are often used interchangeably, so you’ll hear commonly hear people saying that their turtle is ‘hibernating’ and that’s okay — you know what they mean!
In the wild, red-eared sliders brumate from October to March or even April, whenever the temperatures fall below 50 degrees Fahrenheit. By contrast, in captivity, they will brumate when temperatures within their enclosure are low.
As brumation is a strenuous process, only healthy turtles should be allowed to brumate. So, if you intend to breed your turtles, make sure that they are healthy and well-fed, and then use the tips that we’ve shared today and you can help them along.
It’s a natural process and while it can be dangerous, when it’s done right then brumation is actually good for their physical and reproductive health!
Want to learn more about red-eared sliders? Feel free to check out some cool Red-Eared Slider Facts here before you go!
(sources: https://en.wikipedia.org/wiki/Red-eared_slider#Hibernation, http://infinitespider.com/hibernating-mammals-brumating-reptiles-whats-difference/, https://en.wikipedia.org/wiki/Aestivation)