Are you thinking about getting a pet tortoise but are a little daunted by the prospect of hibernation and the process of caring for it during this time? Or maybe you’re simply curious about tortoise hibernation.
Either way, this article will cover everything you need to know, from what hibernation is to the correct environmental conditions, as well as how to spot potential problems and care for them once they awaken.
Why Do Tortoises Hibernate?
Although hibernation is commonly referred to as a ‘deep sleep’ it’s actually a state of dormancy that many animals enter. In periods of extreme cold or when food is scarce, hibernating animals greatly reduce their metabolic activity and body temperature to conserve energy.
During this time, they can maintain their essential bodily functions by relying on energy stored in their fat reserves.
However, cold-blooded animals such as tortoises do not experience ‘true hibernation’ but instead undergo a similar process called ‘brumation’. This term describes winter dormancy in cold-blooded animals with backbones, such as reptiles.
Healthy tortoises gain numerous benefits from hibernating (or brumating). Advantages include preventing lethargy, promoting successful breeding, preventing overeating, and increasing their lifespan.
Although winter dormancy is a natural and essential biological process for tortoises, it does not happen to every species.
In tropical regions with mild winters, some tortoise species can remain active all year. Common, non-hibernating species include:
- Leopard tortoise
- Sulcata tortoise
- Indian star tortoise
- Red-footed tortoise
Recognizing Hibernation Readiness
In the wild, a drop in temperature will cause tortoises to begin hibernation naturally. Captive tortoises tend to exhibit one or more of the following:
- Changes in Appetite: During the summer, tortoises will increase their food and water intake to ensure they have sufficient energy stores and are well hydrated. As the temperature drops, they will stop eating to ensure their stomach is empty before hibernation.
- Frequent Excretion: Tortoises will urinate and defecate more frequently before hibernation to empty their digestive systems and keep them completely healthy.
- Location: Tortoises will search for a secure and safe area to dig a hole in preparation for winter dormancy.
- Drinking: Their water intake will significantly increase to empty their digestive tract fully.
Before you begin any preparations to assist your tortoise with their transition into winter dormancy, ask yourself the following questions:
- Is your tortoise a hibernating species?
- Will your pet tortoise be at least 3 years old before its first hibernation? Although wild tortoises often hibernate the first year after hatching, this is not recommended for captive species.
- Does your tortoise have sufficient fat stores before hibernating? Underweight or sick tortoises are likely to perish during the dormancy period.
Preparing for Hibernation
Hibernation usually begins around November, but you should consider preparing for hibernation in August. Start closely monitoring your tortoise’s eating patterns at this point, too.
Ensure it’s eating enough and building up its fat reserves so it has sufficient energy storage for the hibernation period.
As hibernation approaches, gradually reduce the amount and frequency of food, providing mainly fiber-rich foods to aid digestion. Eventually, they withdraw feeding altogether.
The length of the fasting period will vary depending on the tortoise’s size. Large individuals (2-3 kg) should fast for 1 month, medium individuals (1-1.5kg) should fast for about three weeks, and small individuals (less than 1kg) should fast for two weeks before brumation.
Ensure your tortoise has constant access to clean water to prevent dehydration and help flush urates from the bladder.
Once your tortoise’s diet is under control, you can assess its health and prepare a safe hibernation space.
Health Checks
Suppose you are relatively new to tortoise husbandry. In that case, I recommend taking your tortoise to a veterinarian so they can conduct a full physical examination to make sure your pet is fit for hibernation.
The vet will weigh your tortoise to ensure it’s not underweight and has sufficient energy storage for dormancy. Additionally, the vet will check for any signs of an underlying illness that may prevent a healthy hibernation.
Sometimes, a screening for fecal parasites or diagnostic imaging may be advised.
To ensure your tortoise is healthy, you can perform a few simple checks in the run-up to hibernation:
- Eyes should be clear of discharge, swelling or inflammation.
- The nose should be mainly dry with no excess, runny mucus.
- Check the tail area for any signs of cloacitis leak and a strong odor.
- Check legs for signs of swelling or unusual lumps.
- The shell should be firm. Any sign of trapped fluid or soft and bad-smelling areas can indicate shell rot.
- Inspect ears for noticeable abscesses.
- Blood spots and/or a red-purple tinge in the month can be a sign of mouth rot.
If your tortoise is mature enough and at a weight that is appropriate for their age, they should be hibernated. If they don’t hibernate, they can become lethargic, less likely to breed successfully and more prone to health issues.
Setting Up the Hibernation Environment
Tortoises will only settle for winter dormancy if they have a safe and secure space, and there are two main methods to achieve this:
Refrigerator Method
A refrigerator is a great place to hibernate your tortoise as it provides a cold and controlled environment. To maintain hibernation, tortoises should be kept above freezing, between 34oF and 50oF.
Only use a unit in which you intend to exclusively store your tortoise, rather than one in which you keep regular food. This is unhygienic and would disturb the dormant tortoise.
Place your tortoise in a plastic container that is slightly larger than itself. Line the bottom of the box with either kitchen paper or a mixture of sand and soil. Make sure the lid of the container has plenty of air holes.
Open the refrigerator door a minute or so a few times weekly to allow oxygen flow. Use a thermostat to monitor the temperature inside the refrigerator to ensure it remains cold and constant.
Box Method
Similarly to the refrigerator method, your tortoise should be placed in a lined, plastic box with a lid with air holes.
This container should be placed in a large cardboard box half-filled with an insulating material, such as polystyrene. Completely cover and surround the plastic box containing your tortoise with the insulating material.
Store the cardboard box where the temperature does not greatly fluctuate above or below freezing for prolonged periods. The insulating material will help reduce temperature variations, but you should use a thermometer to monitor the temperature.
During Hibernation
Even while your tortoise is hibernating, it must be constantly checked and monitored. Hibernation is a vulnerable period of a tortoise’s life, so you must keep up with checks.
Monitoring
The recommended hibernation length for captive tortoises is 3 to 4 months. During this time, it’s essential to monitor your tortoise to ensure it stays healthy throughout the hibernation process.
Before hibernation, you should make a note of your tortoise’s weight. Then, during hibernation, you must visually check and weigh it every couple of weeks.
According to the Royal Veterinary College London, adult tortoises lose about 1% of their monthly pre-hibernation weight. A weight reduction of 8-10% can indicate a problem.
If your tortoise drops more than 10% of its body weight or passes urine during hibernation, it must be woken up early. Additionally, if your tortoise wakes up during hibernation, do not put it back to sleep but allow it to wake up.
You will also need to monitor the temperature of your tortoise’s hibernation enclosure regularly. The optimum temperature for a hibernating tortoise is between 37 oF and 45 oF.
If the temperature drops below 32 oF, your tortoise is at risk of freezing to death. Conversely, if the temperature exceeds 50 oF, your tortoise’s metabolic rate will be too high, and its energy reserves will be used up too quickly. I find when we have milder winters, my tortoises are at risk of waking up early due to the warm temperatures.
Common Problems
Although hibernation is a natural and critical part of some tortoise’s life cycle, it is also when they are most vulnerable to various health issues. Some common concerns during and immediately after hibernation include:
Immunosuppression
During hibernation, a tortoise’s white blood cell count is very low, so their ability to fight infection is significantly reduced.
It’s essential to ensure your tortoise is healthy before hibernation, monitored for the duration, and correctly cared for once they have woken up.
Dehydration
During hibernation, metabolic toxins accumulate, which causes a high blood urea level that can damage the bladder and kidneys.
After hibernation, your tortoise will be dehydrated, and the first thing you should do is get them to drink. Bathing them is excellent for helping them re-hydrate and flush out built-up toxins.
Freezing
This is the leading cause of tortoise death during hibernation. Prolonged temperatures below freezing will kill a tortoise, so monitor the temperature frequently to ensure it stays around 40oF.
Rodent attack
During their dormancy state, tortoises are vulnerable to attacks by rodents as they cannot defend themselves.
Please make sure they are in a well-protected environment.
Weight Loss
Tortoises can lose around 10% of their body weight during hibernation. Ensuring they are a good weight for their age, healthy and have plenty of energy reserves before hibernation begins will equip them with the best chances of survival during this time.
Waking from Hibernation
Tortoises will only enter and remain in hibernation if the environmental temperature is within a specific range, usually between 37oF and 45oF.
As the temperature begins to warm toward 50oF, the tortoise’s metabolism is stimulated to return to its average rate, causing the wake-up process to begin.
For tortoises that are captive or living in areas that have cool climates, the awakening process must be artificially induced.
After between 8 and 12 weeks, it will be time to wake up your tortoise. This process should be done gradually over a few days to keep your tortoise safe and prevent any shocks to the system.
Remove your tortoise from the hibernation fridge or hibernation box and place it warmly above 50oF. Gradually increase the heat until your tortoise is at room temperature. Your tortoise will begin to stir and fully awaken from its long sleep.
Post Hibernation Care
To ensure your tortoise safely recovers from its hibernation, you should follow a few critical care tips.
As soon as your tortoise begins to stir, it would be best to place it in a warm bath. A warm bath will encourage your tortoise to drink, rehydrate and flush its system of toxins.
Providing some glucose in the water is a great way to increase your tortoise’s energy levels quickly. Make sure the water level stays below its chin. You should bathe your tortoise for 20 to 30 minutes twice daily during reawakening.
Whilst in the bath, you can take this opportunity to perform a visual check-up on your tortoise. Perform the same checks that you did pre-hibernation and look for any signs of sickness, such as swelling or discharge. If you notice anything unusual, take your tortoise to the vet immediately.
Following their bath, move your tortoise to a warm area. Use a heat lamp so you can regulate and maintain a constant temperature. This should be around 85oF. You should also provide UV light, stimulating an eating response and increasing your tortoise’s appetite.
Once your tortoise is hydrated and warm, it’s time to feed it. Offer plenty of succulent foods to aid re-hydration. Resume feeding your tortoise its regular, high-fiber, low-protein diet thereafter.
Conclusion
Providing a suitable environment for your tortoise to hibernate is more than just creating a safe and secure place to sleep during winter.
Other factors to consider include making sure they are healthy and hibernation-ready before their period of dormancy, monitoring them and their surrounding temperature throughout, and then providing appropriate care post-hibernation, too.
Getting all these factors right will help to mitigate problems and ensure a safe and successful hibernation.
Citations
- The University of Edinburgh – Immunosuppression
- The University of Texas at Austin – Brumation
- Rochford Veterinary – Hibernation Temperature
- RVC – Post-Hibernation Care
- The Royal Veterinary College London – Tortoise Weight Loss During Hibernation
