Hibernating Tortoises

Hibernation is a physiological process in which all metabolic functions slow down to a minimum maintenance level and animal becomes torpid for several weeks, living on its tissue reserves. It occurs in response to cold temperatures and is an adaptive process enabling a species to survive cold periods when food is scarce. Not all tortoises will hibernate. In the wild Mediterranean species, Greek Spur thighed, Afghan or steppe tortoises will hibernate, but the North African species do not hibernate.

Reasons for Hibernation
Helps juveniles slow down their rate of growth which is increased in captive animals In adults decreases onset of obesity.

Should you hibernate your Tortoise?
Firstly you need to check you have a species that will hibernate. Your tortoise must be in good body condition, and if they have been ill over the past 12 months they should not be hibernated. Never hibernate a sick tortoise.

How do you initiate hibernation?
In the build up to hibernation, both photoperiod and temperature should be reduced by increasing the height of the basking source and reducing the ambient temperature.
The tortoise should be fasted 1 month before hibernation. They should be bathed regularly in warm water. This encourages faeces and urine output and ensures adequate hydration.
The ambient temperature should be reduced by 5ºC over a period of
several weeks. Hibernation is initiated by prolonged temperatures below 15ºC and is
maintained between 2ºC-9ºC. Temperatures below 0ºC can lead to serious cellular damage and death.

Common mistakes
Feeding the tortoises prior to hibernation
Hibernating at temperatures >10ºC or <0ºC
Leaving the tortoise with no protection against predators
Hibernating a sick tortoise

How to hibernate a tortoise
1. Cardboard Box
This is an insulated box within a second larger box filled with shredded paper.
This is then placed in a cool place i.e. loft, cupboard. This is not a
recommend technique and has many disadvantages. The cardboard box is
easily chewed through by potential predators and you can not monitor the
tortoise accurately.
2. Refrigerator
The tortoise is placed in a plastic box and placed in the fridge. The box
should contain l soil to allow for burrowing. This technique is useful in
small tortoises as it lowers the risk of dehydration through respiratory water
loss.
3. Indoor Hibernation
This is a purpose built hibernaculum filled with loamy soil and fitted with a
heating element to ensure the temperature does not fall below the thermostat.
Regular monitoring of the temperature is essential.
Checks during hibernation
Weigh weekly
The total weight loss should not exceed 8% over the course of hibernation.
Therefore a weight loss greater then 1% per week is cause for concern and
the tortoise should be woken up.
Check for Urination
Any urine output may result in dehydration. In this situation animals should be
brought out of hibernation and housed in an indoor enclosure.
Movements
Check for signs of activity. This may be a result of high temperatures and
may need readjusting.

Awakening Procedure
The following steps should be taken as soon as a tortoise starts to move
around in its hibernation box in early spring:
1. Examine the tortoise
Inspect its eyes and nostrils for signs of discharge and inside its mouth.
Weigh the tortoise and measure its carapace length using the Jackson ratio
scale to obtain an accurate bodyweight.
2. Warm
Allow the tortoise to warm to room temperature and then place back in their
tables in a temperature within the species preferred optimum range.
3. Bathe
Bath the tortoise twice daily to encourage urination.
4. Food
Offer highly palatable food such as cucumber then once eating
normally introduce their regular diet. If not eating within 7 days please
consult a veterinary surgeon.