If you’re anything like us on cold autumn mornings, we bet many of you would prefer to stay wrapped up warm in bed, instead of having to get up to a cold house and de-ice the car. In fact, maybe we should just sleep through winter, like tortoises! If you own one of these slow-moving little reptiles, you are probably aware that most tortoises hibernate over winter. But knowing when and how to hibernate your tortoise can be tricky, which is why we’ve put together this handy guide that will explain the ins and outs of tortoise hibernation.
What is Hibernation?
Hibernation is a period of reduced activity and metabolic processes, designed to save energy over winter, when food is scarce. Many mammals, like bats, bears and small rodents, hibernate over winter. However, true hibernation is not actually performed by reptiles like tortoises – instead they undergo a similar process called ‘brumation’. For simplicity’s sake, we will still refer to tortoise dormancy over winter as hibernation.
In tropical parts of the world, the winters are not so cold, which means tortoises from these areas do not hibernate. A tropical species can be active all year long (provided it is in a warm environment like its natural habitat). However, many of the most common pet species come from climates where winters are cold enough to need hibernation; check your tortoise’s species and whether they naturally hibernate or not.
When to Hibernate?
So onto the main part of our article – when is your tortoise ready to hibernate? First of all, if you have a tortoise under a certain age and size, it will not need to hibernate – tortoises of this age are still developing, and will not hibernate in the wild. If it’s under three to five years old (dependent upon species), don’t hibernate.
In the wild, a tortoise will actually be preparing for hibernation almost as soon as the last one ends! A tortoise must build up sufficient reserves of body fat, vitamins and water over the summer to last over winter. This means that you should not think about hibernation as it gets colder, but during summertime. Hibernation is a dangerous period for a tortoise, and they must be fit and healthy to survive – this is why adequate preparation is necessary. In mid-August, it is worthwhile getting a vet or reptile specialist to assess your tortoise’s health – if they give the all clear, you can let them hibernate this year. If not, do not let them hibernate.
Preparing for Hibernation
If you’ve decided to let your tortoise hibernate over winter, you can continue mostly caring for them as normal until late-October. However, because our summers are shorter than in the Mediterranean (where most pet tortoises are from), you should bring them inside into a vivarium, with a heat lamp, once the nights start getting colder. This is to artificially extend their summer, and keep them active and feeding until it is time to hibernate – if they start to slow down too early, they may not have enough body stores of fat for a prolonged hibernation.
Reaching late-October, the hibernation process begins: over a few weeks, gradually reduce your tortoise’s environmental temperature in the day and night, and the size of their meals too. They should be eating less and less as they become less active. After a few weeks, stop feeding completely and wait for two weeks with no more food given. One of the biggest dangers tortoises face during hibernation is having food in their stomach rot and cause disease – this two week period of starvation before hibernation-proper allows them to fully empty their stomach of food. Water should still be provided at all times. By now, it will be around November.
The Hibernation Period
The hibernation period should not be longer than 12 weeks, meaning a tortoise put into hibernation in November will be brought out around the start of February. There are many different methods of hibernation, so we will only briefly go over some here. However, the most important thing to remember is that their environmental temperature must not go below 3°C or above 10°C – too high and it may wake up and use excess energy, while too low and there is risk of freezing to death. It will be down to individual owner where they choose to hibernate their tortoise. Common locations include the fridge (no really! Fridges are usually 3-8°C… Just check the settings to make sure it’s not too cold; 4-7 is generally ideal), outside in a garage, or another temperature controlled environment.
Your tortoise should be stored in a small box, like a shoebox, with adequate ventilation. Inside should be plenty of insulation, such as soil, newspaper or other warm material. It is a good idea to store this box inside a larger plastic tub (poke holes in the top first), to prevent it burrowing out should hibernation fail and your tortoise wake up early.
Weigh your tortoise just before putting them away hibernation. A tortoise should lose around 1% of its mass monthly, so a three month hibernation for a 1.5kg tortoise results in it losing 45g over the period. The myth that you should not disturb a hibernating tortoise is untrue, as you should regularly check on them and weigh them. If they have urinated, immediately take them out of hibernation, as they are at risk of dehydration.
After the maximum 12 week period, your tortoise is ready to wake up – this should be done gradually by slowly warming them up at the end of hibernation. Watch them and provide food and water; they should drink very soon. If they do not, a shallow bath can provide hydration instead. Any worries after this? Then see a vet immediately – not drinking after 3 months without water can be fatal.
If your tortoise was not healthy enough to hibernate this year, keep them inside. Use a temperature controlled vivarium, feeding and watering them as normal over the winter.
Tortoise husbandry is quite a complex topic, so this article provides the most important details on the hibernation process. Anyone wishing to own a tortoise, or who wants to know more about theirs, should definitely do plenty of research. Nevertheless, we hope that we have given you lots of useful advice on why, when and how to prepare for tortoise hibernation.