All tortoise keepers should seriously consider providing a cooler period for their tortoises and there are a lot of reasons for this..
The biggest problem nowadays is that young tortoises are growing too quickly, which can be problematic and cause health issues. The other problem is of which I am constantly being asked about is that our tortoises are not eating or are sleeping a lot. This is because tortoises naturally want to hibernate. Giving them a short, controlled hibernation can help re-set their body clock and encourage them to feed better and reduce their stress.
Which species really should hibernate?
Some of the most popular species of pet tortoises have reached their status because of their tolerance to the UK climate. Many of these come from areas across southern Europe and North Africa and fair extremely well outdoors through most of the year. These are the Hermanns (Testudo hermanni), Horsfield (Testudo horsfieldii), spur-thighed (Testudo graeca) and marginated tortoises (Testudo marginata). All four of these species should be hibernated or at least experience a dormant period. Tropical species such as red-footed (Chelonoidis carbonarius) and yellow-footed tortoises (Chelonoidis denticulatus) will not experience such drastic temperature drops and therefore should not be hibernated. The same applies to popular desert species such as sulcata (Centrochelys sulcata), leopard (Stigmochelys pardalis) and pancake tortoises (Malacochersus torneiri).
Typically, Hermann’s, Spur Thigh "dark-shelled" Ibera and Horsfield tortoises will hibernate extremely well. If they are healthy, they are very hardy species and hibernation is considered beneficial, if not essential for their wellbeing.
Normally hibernation would happen when temperatures drop below 10°C, but a constant 5°C is a far safer temperature for these tortoises to get some sleep, Horsfield tortoises are some of the most northernly ranging tortoises and therefore require a slightly cooler temperature to hibernate. Anything much higher than about 6°C and the keeper may find that they will scratch away in the box and not go to sleep straight away. In the case of Horsfields', the keeper should aim for 3°C – 5°C. They are also extremely intolerant to dampness, so be mindful that the box must not be damp.”
If you keep a Marginated tortoise, I would be very careful about putting your tortoise into any long term hibernation unless you are a very experienced keeper. These tortoises can run into trouble if not hibernated and monitored properly. This goes for light shelled Spur thighed tortoises and other species that come from a climate that doesn’t cool down for longer periods of time. I would only recommend a period of cooling off for these species.
Your Tortoises health matters
When thinking about hibernating your tortoise it is imperative that your tortoise is fit enough to get through the hibernation period you set. All tortoises will differ in the period of time that they will naturally sleep, and there are a few deciding factors that need to be considered before you put your tortoise into hibernation.
A experienced keeper will get to know their tortoise, they will know it’s eating, drinking habits and even its bowl movements. Keeping a log of your tortoises habits is really important and will help you decide how healthy your tortoise is. The tortoise should have nice bright eyes, a pink tongue, no sores around its tail or swollen joints. You should also smell your tortoise and make sure there are no foul smells which would indicate a problem. A healthy tortoise should always have clear nostrils and eyes. By doing all these checks and constantly monitoring and recording your tortoises weight will tell you how well your tortoise has done throughout the spring and summer and with that knowledge you will know how long you should hibernate your tortoise for. I would probably only hibernate my tortoises for a maximum of 12 weeks if they are on top form, for those that haven’t done as well I would only recommend up to an eight week period. If you think your tortoise is underweight but has fed well and passed all other health checks then you should still be hibernating your tortoise but just for an even shorter period of time. If you have concerns about the health of your tortoise then please consult your local herp vet. An experienced Herp Vet is worth its weight in gold in my experience and will always be able to put your mind at rest on whether you should or shouldn’t hibernate your tortoise. Always remember that there must be a very good reason not to hibernate as the benefits for your tortoise to hibernate are much higher than deciding not to hibernate.
When to hibernate?
Choosing when to hibernate can be tricky due to the current UK climate being so unpredictable. The temperature can drop to under 10°C in September but this doesn’t mean that it’s the same temperature in Europe where your tortoise comes from.
If the temperatures are dropping in September/November it doesn’t necessarily mean you should rush to start your Tortoises hibernation period. It is good practice to try and keep your tortoise awake as long as possible whilst there is still some natural foods in the wild to gather. You should now be thinking of bringing your tortoise inside to offer it a little extra warmth. Putting up an indoor enclosure doesn't need to cost you a fortune as it will only be temporary, you can use all sorts of materials or ready made containers. It will be necessary to provide a basking lamb and a UVB light or if you have a combination bulb that would be perfect. Always ensure your bulb is not too old, it may look bright but the UVB capacity may not be sufficient enough. An ambient temperature of 16°C at night and a 30°C basking area for the daytime this temperature should be slowly reduced along with the amount of daylight hours you are giving it, this should go down to around 6 hours per day and then the final few days before hibernation do not give any daytime lighting at all.
During this cooling off period you should maintain a good diet with supplements and calcium slowly switching to a more bland diet such as fruit and salad (rich foods can rot in the tortoises tummy which can cause an infection.) Around a month before your hibernation date you should just watery salads and offer your tortoise plenty of fluids, warm baths are also good around this time. it will take at least 4 weeks of fasting for you tortoise to completely empty its stomach. A few days before hibernation a good all over clean will ensure your tortoise is free from any nasty bacteria that may stick around during hibernation. Use a soft toothbrush to give your tortoise a coating of Tamodine making sure you get into all the nooks and crevasses.
Where to hibernate?
Historically, many keepers opt for the ‘box’ method. This sees the animal placed inside a box with some newspaper shredding and placed in the coolest room in the house. Hay/straw should be avoided as it can bind around the tortoise’s joints. The addition of more mass will help stabilise temperatures, therefore having a box within another box is going to be much more reliable. A temperature probe should be inserted into the inner box, housing the tortoise. The box should also be labelled clearly and placed somewhere secure. The box should be placed on the ground to avoid it falling, if the tortoise moves around and unbalances it. It should also be away from any potential predators. Lofts, conservatories and wooden sheds will also experience major temperature shifts. Unless you are lucky enough to have a brick or stone outbuilding, the box method is not a great option due to the possibility of extreme temperature changes that we can experience here in the U.K
In mainland Europe, many keepers including myself will opt for the ‘natural method’. This involves creating a brick-lined pit in the garden for the tortoise to hibernate in at their leisure. All precautions should be made to keep this area dry as the U.K has a much wetter climate. Some UK keepers are extremely successful at keeping European species outdoors year-round by producing impressive hibernacula, but for the average pet owner, this can be tricky to navigate. For all methods, the keeper must ensure that the box is secure and predator-proof. This applies not just to cats and foxes, but to rats and mice which can also attack a hibernating tortoise.
The most popular choice is the ‘fridge method’. Modern housing is typically very well-insulated, so finding a location in the home with a steady 5°C temperature can be challenging. A fridge, on the other hand, can be a more predictable option if it is in good condition. The most important thing to consider when choosing a location to hibernate a tortoise is ensuring a steady, consistent temperature. A fridge that has a freezer compartment is extremely risky as a damaged fridge may lead to part of the fridge freezing. If you decide on using this method all keepers must consider. Firstly, remember to open the door every few days to make sure that there is always enough oxygen. Secondly, check the temperatures several times in the run-up to hibernation to ensure that the temperature is steady. Finally, the addition of a few large bottles of water will add mass, which should then support the stability of the temperature. The tortoise should be placed in a plastic container, with a deep layer of soil-based substrate to allow it to dig into a comfortable position (leaf-litter can also be added for extra security) and placed into the fridge. Soil should not be soggy and should be able to crumble and fall off the keeper’s hand. Alternatively, the keeper could place the tortoise on a towel with dried leaves or shredded paper on top. If this method is chosen, a bowl of water should be added to the fridge to allow some ambient humidity.
Reassurance and Peace of mind
Leaving a beloved pet to their own devices, asleep in the fridge, can be a daunting prospect for any keeper. They shouldn't be disturbed too much during this period, but there are a few ways that a keeper can check up on their animal. Firstly, a data log of minimum and maximum temperatures is an excellent tool to monitor the conditions of the tortoise, whilst also providing some peace of mind for the keeper. Tortoises will typically sleep with their legs spread out. If the keeper touches the animal's leg, it should move slightly which is a good indicator that the tortoise is still alive, without disturbing its hibernation entirely.
Rest assured that it is perfectly normal for the tortoise to move around in its box for up to 10 days after being hibernated. It might seem odd to the keeper, but a bit of movement is normal. If the tortoise urinates in the early stages of hibernation, there’s nothing to worry about. If it defecates, the keeper may need to remove the tortoise and fast it for a little longer before trying hibernation once again. If it happens at a later stage, this would be a cause to cut hibernation short. Once hibernation ensues, the number one most important thing is to keep the temperature steady. The steadier the temperature, the less stress on the animal and the less chance of it losing excessive weight.”
After the hibernation process, the tortoises can be warmed up to room temperature gradually over 48 hours. Eventually, they can be reintroduced to their indoor enclosure and placed under a basking light which will kickstart their feeding behaviour. If the tortoise does not feed within a week of waking from hibernation the keeper should offer tempting favourite foods, hand feeding opportunities and daily soaks. If these do not work, the tortoise may need to be force-fed with the support of a knowledgeable vet or expert. A slow starter can sometimes benefit from Reptoboost soaks post-hibernation. This is designed to replenish electrolytes, vitamins and probiotics.
In the wild, tortoises will often awake to find plenty of fresh spring shoots to feed on. In this case, feeding crunchy moisture-filled salads such as crunchy romaine, baby gem lettuce, rocket and even some cucumber is great. However, cucumber is mostly filled with water. It is great for a drink, so it is really useful after waking the tortoise up, but it is not very nutritious. Keepers should be aiming to move their tortoises onto more fibrous foods as soon as possible, so going out to collect as many weeds as possible is important. These can be kept in sealable sandwich bags in the fridge. It’s a good idea to ask friends and family with pesticide-free allotments and wild gardens to collect these for you as often as possible. It’s free and they have much more trace elements and nutritional value than store-bought salads.”
Calcium and vitamin supplements are also incredibly important at this time of year. Even the very best natural weeds will have less nutritional content in spring and autumn than they will in summer. Therefore, high-quality calcium and vitamin supplements are essential. These can also expire and lose potency over time, particularly if they have been left open for a long period so keepers should aim to pick up fresh tubs of supplements ready for when the tortoise emerges from hibernation.
Ron’s Pet Supplies can provide you with all your tortoises nutritional and supplement needs along with a safe feeding guide if you are gathering wild plants and flowers. Please ask a member of staff for more information
Thank you
Information in this article has been provided by the Exotic Keepers Magazine and Gavin’s first hand experiences in keeping and hibernating his own Herman’s tortoises.
