Along with their reputation for being slow and nervous, tortoises are well known for their natural need to hibernate (also known as brumation) during the winter months. Of course, just like their reputation for being slow, this is a stereotypical and naive viewpoint, because whilst many tortoises do hibernate, there are several species that don’t. Knowing if your tortoise does hibernate or not will inform your plan for managing them to help make sure they stay healthy.
Even if you own a hibernating breed of tortoise, there are arguments for and against hibernating them, which you can read about here.
Which Species of Tortoise do not Hibernate?
If your tortoise if of a species that hails from the tropics, then there’s a strong chance hibernation won’t form part of his/her yearly routine.
The tropics are essentially areas in the world that fall within a band of the earth’s surface either side of the equator, bound by the Tropic of Cancer in the Northern Hemisphere and the Tropic of Capricorn in the Southern Hemisphere. Countries and regions that fall within these areas are known for having a climate that’s warm (at least 18 °C or 64.4 °F) all year round. Typically these regions only have two seasons; a wet season and a dry season.
What this means for a tortoise living in the tropics is that the temperature never gets sufficiently low enough as to prompt or warrant hibernation, hence all species that come from these regions have evolved without a natural need to hibernate.
Essentially any species that comes from within the tropics, whether African, South American, or Asian falls within the non hibernating category.
Popular Tropical Tortoises:
- Red Footed Tortoise
- Cherry Head Tortoise
- Indian Star Tortoise
- Leopard Tortoise
Any good breeder or pet shop should be able to tell you whether your tortoise is a tropical species or not, but my advice is always to ask if you’re not sure, and do plenty of research in advance.
Which Species of Tortoise Do Hibernate?
Basically any species that isn’t tropical! Mediterranean species such as Hermann’s and Spur Thigh tortoises, as well as Russian tortoises and species native to North America all hibernate for between several weeks to several months of the year.
How Old Should My Tortoise Be Before Hibernating?
This is a contentious one; I’ve been told first hand by several reliable sources (including the breeder who sold me my Hermann’s) that it isn’t necessary to hibernate a tortoise for the first 5 years of its life. Elsewhere the consensus seems to be that hibernation from the age of one onwards is not only fine, but vital to the proper development of the tortoise.
The argument for hibernating sooner is to prevent the tortoise from growing too quickly. Although this doesn’t sound like a problem, it can actually lead to health problems such as metabolic bone disease, symptoms of which can be a soft or deformed shell that doesn’t grow quickly enough compared to the rest of the tortoise. This can actually be worse during the early years of the life of the tortoise when they’ve yet to reach full size. Hibernation allows growth to take place at the correct rate.
If you can ensure the correct set-up for hibernation there’s no reason not to hibernate a tortoise from the age of one onwards, it will just be for a shorter amount of time than an older specimen.
However if you’re not confident for any reason, keeping your tortoise awake all year round until the age of about 3 is okay, but you’ll certainly want to hibernate them the following year.
The approximate duration of hibernation according to the age of your tortoise should be:
1st year – 3 weeks
2nd year – 6 weeks
3rd year – 10 weeks
4th year – 16 weeks
5th year onwards – 22 weeks
What Time of Year Does a Tortoise Hibernate?
Generally speaking tortoises in the wild will ‘wind down’ for winter when the nights grow longer in around late October and Early November. Obviously you can have a little bit more influence over when your own tortoise will hibernate, but you’ll start to notice them get more lethargic around this time of year, signifying that they’re ready for hibernation.
Preparing For Hibernation
The golden rule when preparing your tortoise for hibernation is to make sure they have an empty stomach. If they hibernate with food in their gut it can prove fatal, so it’s vital you develop some sort of strategy to mitigate this risk.
In around mid October you should start to look for signs of lethargy in your tortoise; he’ll probably be moving around less, and perhaps eating less food than usual. As soon as this happens you’ll need to cease providing further food for a further two weeks if the tortoise is under 3 years old, and a further month if they are over 3 years old.
Whilst food is taken off the menu in the run up to hibernation, water most certainly is not. In fact you’ll need to make sure your tortoise has a full bladder before they have their long sleep, therefore daily bathing is essential to ensure the maximum uptake of water. This also serves the secondary purpose of helping to clear out the gut of any remaining solids.
Weighing
If you’re hibernating your tortoise for the first time in its life you might want some additional information to help you decide whether or not he or she is ready. One such method is to weigh your tortoise to see how they compare to the ‘ideal’ weight for their age.
Whilst there are a couple of different weight and size ratio charts to compare your tortoise to; chief of which is the Jackson Ratio, it’s important to remember these charts should only be used as a guide, ultimately you’ll need to use your best judgement alongside the data they provide.
Note also that the Jackson Ratio is only applicable to Hermann’s and Mediterranean Spur Thigh tortoises.
The Jackson Ratio requires the length of the shell from end to end (known as the straight carapace length). The easiest way to measure this is the place the tortoise on a piece of paper with the back of the shell and one edge of the paper hard up against a wall. With the tortoise’s head retracted you should then be able to mark off the position of the front edge of the shell on the piece of paper.
Weighing the tortoise is a job suited to digital kitchen or parcel scales, rather than the type you might use to weigh yourself which probably won’t be accurate enough. You’ll want to pick a time when your tortoise has an empty gut and bladder to get the most accurate result with the scales.
Setting Up The Right Location To Hibernate
The difficulty when selecting a location for your tortoise to hibernate is finding a spot where you can ensure the temperature will stay consistently within the 2-10 degree bracket. Lower than zero and the tortoise could freeze, more than 10 and they could wake up prematurely.
The key is placing whatever container you plan to house the tortoise in, in a relatively stable environment such as a garage or shed. This provides shelter from adverse weather and predators, whilst certainly not getting too warm.
As for the container you plan to place the tortoise in, let me first say that you should avoid insulating this with shredded paper, straw, or anything else that could get wrapped around the tortoises neck. I’ve unfortunately known several people to lose a tortoise this way, so I know first hand that it’s not a good idea.
In any case you should actually use a container within a container, such that any insulating material doesn’t actually come into contact with the tortoise at all.
the smaller inner container is where the tortoise will be sat. It’s best to use a plastic box of an appropriate size for the tortoise that’s also large enough to line the base of with a layer of moist sterilized compost (this helps prevent the tortoise from getting dehydrated during hibernation).. The lid will need to have several air holes in it.
The outer box can simply be a cardboard box, or if you prefer a larger plastic container. The smaller box with the tortoise in should be placed in this larger box and insulating material placed between them. This could include shredded paper (as it won’t be in direct contact with the tortoise) or polystyrene packing ‘peanuts’. Once again this larger box should have air holes in it, and there should be a clear path for the flow of air into the smaller inner box.
Having an insulated container arrangement like this should keep the temperature inside consistent for the tortoise, however it’s a really good idea to have a digital thermometer with a temperature probe located in the inner box so that you can regularly check the temperature doesn’t exceed or drop below the acceptable range.
Using a Fridge?
This is a slightly more unorthodox method of storage for a hibernating tortoise, and on the surface it seems ideal; you have full control over the temperature of the space, and it’s well insulated to maintain said temperature.
My biggest concern over using a fridge however is that they are airtight. So if you do choose to use one you’ll need to modify it by drilling 2 holes in the fridge door, one to pump air in, and another to allow return air to come out. An air pump will also need to be used to ensure a positive flow of air.
There’s also the temptation to use an old fridge instead of a new one, however this is a risky strategy as depending how old your ‘old’ fridge actually is, the thermostat might not be as reliable as it should be, therefore the danger of the fridge being warmer or colder than it actually should be could prove fatal for the tortoise.
The other vital piece of the puzzle is ensuring that the ambient temperature of the room you intend to keep the fridge in remains constant. Although a fridge is indeed designed specifically to insulate the inside temperature from the affects of the outside, it’s never 100% efficient. The biggest danger comes from the room being too cold, if for example the temperature of the room drops to -3 degrees celcius, then this will have an impact on the temperature inside the fridge, potentially taking it down below zero, and once again proving fatal.
Waking Up Early
If your tortoise wakes earlier than expected then you shouldn’t try and put him or her back to sleep, their metabolism will have switched back into ‘waking’ mode and it would be dangerous to try and force hibernation again as chances are they wouldn’t be able to and you would risk them dying of thirst or starvation.
The most common lesson to be learned from a prematurely waking tortoise is that the temperature in or around their hibernation container probably rose too high, prompting them to wake. Therefore the following year you’ll probably need to be more attentive at monitoring the temperature.
Waking As Expected or Up As Prompted By You
When the time comes for your tortoise to come out of hibernation you’ll need to move the their hibernation container into a warmer space, typical room temperature (21 degrees Celcius or 69.8 Fahrenheit is sufficient to gradually get them moving again). After an hour or so you can move them out of their hibernation box and back into their tortoise table or vivarium. Here they’ll get a much needed dose of UV light as well as continued heat.
Post Hibernation Feeding
As you can no doubt imagine, your tortoise will be pretty famished having not eaten or drunk anything for many weeks! You’ll probably even notice they look a bit on the skinny side, but this is usually nothing to worry about, as long as they tuck into their food and drink soon after waking.
Once they’ve begun to reacclimatise and move around a bit you can start to offer food and water. Just as with ourselves, water is more important for survival than food, so bathing your tortoise for 10 minutes rather than simply filling up their water dish will ensure they actually take on some water.
