Hibernation of Tortoises: How to Prepare for Winter?

As autumn approaches, subtle changes gradually take place in the outdoor enclosure. Your tortoise still enjoys a few rays of sunshine, nibbles on the plants around it, and then returns to its shelter. Its outings become shorter, it moves around less frequently, and its appetite gradually decreases.

When observing this phenomenon for the first time, it can be quite puzzling. Should you continue feeding your tortoise? Is it simply less active because of the cold? Is it already preparing for hibernation?

In Hermann’s tortoises and other species that hibernate, these changes are a natural part of their annual cycle.

So, what is really happening? And above all, what preparations should you make to help your tortoise get through the winter in the best possible conditions?

When Temperatures Drop, the Entire Body Slows Down

A tortoise’s body temperature depends on its environment. As cooler days arrive, its metabolism naturally begins to slow down.

It moves around less, its digestion slows, and it gradually reduces its food intake. Hibernation then allows it to get through the cold season by conserving energy and relying on its reserves.

However, it is important not to generalise: not all tortoise species follow the same seasonal cycle.

Before preparing for winter, it is therefore essential to identify your tortoise’s species accurately and understand its specific needs. The conditions suitable for a Hermann’s tortoise cannot automatically be applied to all other tortoises.

What About Young Tortoises? They Hibernate Too

It may be tempting to keep a very young tortoise active during its first winter, simply because it still seems small and fragile.

However, in Hermann’s tortoises, hibernation is part of the natural cycle from the very first year of life. In the wild, young tortoises also go through this period of rest.

Their small size alone is therefore not a reason to prevent them from hibernating. However, their health and the conditions in which they will spend this resting period require particular attention.

A veterinarian experienced in treating reptiles and other exotic pets can assess whether they are fit to hibernate and recommend appropriate preparations. A young tortoise that is weak or ill should not be allowed to enter hibernation without veterinary advice.

No Fixed Date: Your Tortoise Sets the Pace

Hibernation does not begin simply because a particular date appears on the calendar.

As the days grow shorter and temperatures fall, the tortoise gradually adjusts its behaviour. It ventures out less frequently, spends more time in its shelter, and eventually stops eating.

In fact, preparation for hibernation begins long before autumn.

A well-planted outdoor enclosure allows the tortoise to graze on suitable wild plants throughout its active season, such as dandelions, mallows and wild chicory. This vegetation should be varied, correctly identified and free from chemical treatments.

As hibernation approaches, there is therefore no need to encourage your tortoise to eat more "to build up its reserves". Its preparation depends primarily on the suitable conditions it has enjoyed throughout its active period.

Before Hibernation, Check Your Tortoise’s Health

A tortoise that becomes less active in autumn is displaying expected seasonal behaviour. However, the season should not automatically be used to explain every change in behaviour.

A health check with a veterinarian experienced in treating reptiles and other exotic pets can help assess its overall condition and whether it is fit to hibernate. It is best to arrange this sufficiently early so that, if a problem is detected, there is still time to address it before hibernation begins.

Weighing your tortoise also provides a useful reference point.

However, weighing does not replace observing the animal or having it examined. Nasal discharge, abnormally closed eyes or weight loss are particular signs that require attention.

To Hibernate Outdoors, Your Tortoise Must Be Able to Burrow

A shelter filled with leaves and simply placed on hard ground does not allow a tortoise to bury itself as it would naturally do in soil.

For natural hibernation, it is therefore essential to provide soil in which the tortoise can burrow.

A hibernation pit can be prepared by loosening the soil to a depth of approximately 50 to 60 cm. This does not mean your tortoise will necessarily bury itself 60 cm deep! This depth simply ensures that enough loose soil is available for it to choose how deeply it wishes to burrow.

The design must, of course, take into account the characteristics of the ground and the local climate.

Choosing the right location is particularly important. The area must be well drained and away from places where water tends to accumulate. During heavy rainfall, the hibernation pit must never become waterlogged.

A shelter installed above the pit helps protect the area from excessive rainfall.

It is also best to plan ahead: this preparation must be completed before the tortoise chooses its winter resting place. Once it is hibernating, the aim is to avoid disturbing the soil around it.

Fallen Leaves for Additional Protection

Once the tortoise has buried itself, fallen leaves can provide additional protection for the hibernation area. However, not all leaves decompose in the same way. Some break down quickly and may eventually form a compact layer.

Oak leaves have the advantage of decomposing relatively slowly, making them a particularly suitable choice.

Once the tortoise has burrowed into the soil, a layer of thoroughly dry oak leaves can be placed over the ground. This helps reduce temperature fluctuations and provides additional protection.

However, leaves complement the protection provided by burrowing; they do not replace it. The shelter must also protect them from heavy rainfall, and during prolonged freezing conditions, this layer alone may not provide sufficient protection.

An Often-Overlooked Danger: Rodents

During hibernation, a tortoise is sluggish and particularly vulnerable. It may be exposed to attacks from rodents.

The hibernation pit can therefore be equipped with sturdy, fine-mesh wire netting to help prevent rodents from gaining access, while still allowing the tortoise to burrow normally.

However, even with a carefully protected setup, the risk cannot be completely eliminated. It is therefore important to continue checking the shelter regularly throughout the winter.

Monitor, Yes. Disturb, No.

A tortoise buried for the winter does not need to be dug up to check that everything is fine. Monitoring should primarily focus on what is happening around it.

After heavy rainfall, check that water is not accumulating in the hibernation area. During a cold spell, make sure the protective measures are still properly in place. Signs of animal activity or damage to the shelter may also indicate the presence of rodents.

The aim is to monitor the tortoise’s environment without disturbing the soil or interrupting its rest.

Of course, there are situations where intervention becomes necessary. For example, if the hibernation area is threatened by flooding, the tortoise must be moved to safety, and advice should be sought from a veterinarian experienced in treating reptiles and other exotic pets.

What If Your Tortoise Needs to Hibernate in a Box?

Certain situations can make natural hibernation in an outdoor enclosure difficult to maintain. This is particularly the case when a move is planned during the winter.

A hibernation box can then provide a resting place independent of the outdoor enclosure. However, once again, it is best to prepare everything before the tortoise has entered deep hibernation. The essential point is not to place a tortoise that is still awake and active into the box. The transfer should take place once it has begun hibernating.

A sturdy, sufficiently deep box is filled with loose, untreated garden soil. The tortoise is gently placed on the surface: it should not be buried by hand. It must be able to burrow naturally into the soil. Once it has buried itself, a layer of thoroughly dry oak leaves is added on top. The box must remain well ventilated, with its openings protected by fine-mesh metal wire to help prevent rodents from entering.

It should then be placed in a quiet, dark, frost-free location where the temperature remains stable at around 5°C. Care should be taken to keep the temperature below 7°C to minimise the risk of the tortoise becoming active again during hibernation. Another important factor to monitor is soil moisture.

Without digging up the tortoise, regularly check that the substrate does not dry out completely or become waterlogged. If necessary, the soil can be lightly moistened to prevent excessive drying. Finally, the timing of the transfer and the transport conditions should be planned with a veterinarian experienced in treating reptiles and other exotic pets, minimising vibrations and temperature changes as much as possible.

While Your Tortoise Sleeps, Its Enclosure Can Already Be Prepared for Spring

For several weeks, the outdoor enclosure may suddenly seem very empty. However, this period can be put to good use by preparing for the following season.

Without disturbing the area where your tortoise is hibernating, you can improve other parts of its enclosure, consider expanding it, check the fencing, create new hiding places or plant suitable vegetation for its diet.

Any work should simply be carried out far enough away from the resting area to avoid disturbing its hibernation.

When the first favourable days return and your tortoise gradually begins exploring its enclosure again, everything will already be ready to welcome it back. And it may even find a few new plants to discover… and, above all, to graze on.