HIBERNATION OF ADULT AND YOUNG TORTOISES

It is a natural process for most species of tortoise to hibernate and they would do so if they lived in the wild. I must express, that it is imperative to find out exactly what species of tortoise you keep, as some do not hibernate and to do so would be fatal. Some of these species include the Sulcata (North African Spurred), Leopard and Tunisian (Furculachelys nabeulensis), Kleinmanni and all tropical tortoises.

In the wild most tortoises would naturally hibernate, including hatchlings. They would shadow the adults in every way. Hibernation helps to prevent excessive growth which is all too often seen in captive bred tortoises. My advice is to let nature take its course and do what is right by your tortoise. Although it may be worrying, with good care and advice you will be giving your tortoise a life that is natural to them.

Tortoises in general begin to slow down as the days become shorter and the temperature becomes colder.

Sometimes, even though we try to replicate the summer months by using additional heating (basking lamps) and UVB lighting, some tortoises still know that the time for hibernation is approaching and it can be quite difficult to change their minds.

Firstly no sick, injured or underweight tortoise should be hibernated.

Choose your hibernation method well in advance, so as you can prepare the necessary requirements for a safe winter sleep.

HIBERNATION METHODS

1)       Refrigeration method

2)       Box method

3)       Natural hibernation

The Jacksons Ratio is a weight and length chart that will advise you if your tortoise is within safe limits to be hibernated. This chart can be printed off of the tortoise trust web site. www.tortoisetrust.org. On this web site you will also find advice on the correct way to measure your tortoise. The measurement should be done in a straight line NOT over the carapace (upper shell). The entire length should be from head end of the shell (nuchal) to tail end of the shell (supracaudal). This is important as the wrong measurement will result in an inaccurate reading.

This chart does not cover all species of tortoise. The more popular garden tortoises, Hermann’s, spurthigh graeca and spurthigh ibera are the only ones accepted. The Marginated and Horsefield’s tortoises to name a few, are not suited to this graph.

You should take several readings to gain an overall average result. It is surprising how much the weight changes due to defecation and urination.

You will need to do a visual check of your tortoise to ensure signs of good health. Check as instructed below.

1)       Eyes should be checked for inflammation or discharge. Both eyes should be bright and clear. Sunken eyes are also a sign of ill health.

2)       The tail should be checked for discharge or smell. Also look for inflammation or reddening.

3)       Feel around the legs for any unusual swellings or lumps and generally examine the entire skin area for abrasions or parasites.

4)       Check both ears for swellings. It is quite common for tortoises to get abscesses. The ears should be either flat or slightly concaved.

5)       Open the mouth and look inside for any sore areas or red/purple colouration. Make sure it is clean and that no cheesy like substance is visible. This is a sign of mouth rot and needs urgent medical attention.

6)       The nose must be clean and dry. If the nase are swollen or have any sign of discharge then again medical attention must be sought.

Once you have carried out the health check and weighed your tortoise, if everything seems fine then you can move forward to hibernating safely. If in any doubt contact a reputable tortoise specialist vet who will advise you of the safest option to take.

To put a tortoise into hibernation with a full gut will cause fatalities. The food decays in the stomach which produces toxins and gases. It can take anything from 3-6 weeks for the food last consumed to be digested and pass through the intestines.

Smaller tortoises take less time for the contents to pass through, approx 3 weeks. Adult tortoises can be anything from 4-6weeks depending on size and temperature.

If temperatures are below 10 degrees then the tortoise will begin to shut down.

As the days become shorter and the temperature cooler young and small tortoises should be brought in to a warmer location. Their hibernation time will be shorter than that of the adults, 8-10 weeks. Indoor housing with additional heat (basking lamp) and UVB lighting is essential to encourage activity and feeding. Hatchlings and juveniles have a smaller body mass and are more susceptible to the cold and will freeze much quicker. My motto below 10 indoor pen.

Adult tortoises in hibernation should lose no more than 1% of its actual body weight per month.

You can and should weigh a tortoise during hibernation and I would recommend regular weight checks to make sure that the weight loss is minimal. If you notice your tortoise is losing too much weight then it should be brought out of hibernation early and over-wintered in a warm environment to encourage natural behaviour of activity and feeding.

WIND DOWN FOR SMALL TORTOISES

Week one

Provide heat (basking lamp) and UVB lighting to encourage normal activity and to allow the metabolism to work. DO NOT OFFER FOOD, bath daily in warm water to encourage fluid intake. Reduce the heat and light daily.

Week two

Reduce the heat and light further until they are only getting a few hours per day. Continue to regularly bath, but do not offer food.

Week 3

No lighting at all, but room temperature for the first part of the week. You will notice your tortoise becoming less and less active. Continue to bath for the first part of the week. Last part of the week move the enclosure to a cooler room and cool it further as the week progresses.

For adult tortoises the wind down period should be for 4 weeks.

During this time NO FOOD should be given.

The tortoise needs to be kept above 13c to allow its stomach contents to pass through. If it is colder than this outside then either an outdoor heat source should be provided or the tortoise should be provided with a warmer area. The higher the temperature the quicker the stomach contents will digest and pass through.

Warm water bathing 3 or 4 times a week is essential.

5 degrees celsius is the optimum safe temperature for hibernation. If temps drop below 4c or above 6c then close observation is required. If temps continue to drop or rise then action must be taken to move your tortoise to a more stable area. Always use a digital thermometer to get an accurate reading.

Once your tortoise has shut down with the cooler temperatures then it is time to move it to a safe hibernation area, which you will have decided previously.

Never move a tortoise from a warm area straight to a cold hibernating area. A gradual cooling process is a must.

Box method

You will need 2 boxes. An outer wooden box to prevent predators and an inner smaller box full of substrate. If you are hibernating hatchlings or small tortoises, I would recommend the inner box substrate to be of soil and sand. John Inn’s no1 and children’s play sand. A good depth is required to allow them to bury and completely cover themselves. Soil and sand provides a denser coverage and they can dig down to their preferred depth. For larger tortoises HAND shredded paper can be used. Also straw and hay can be used, but this would be my second choice as it can harbour mould spores. There should be enough room in the inner box for the tortoise to be placed comfortably and still allowing for a good few inches of insulating material all around the tortoise.

Between the inner box and outer box, an insulating material such as polystyrene chips or again shredded paper should be added and packed tightly to safeguard them from cold temperatures. Always use a digital thermometer to ensure your tortoise is within safe limits, ideally one with a probe. The probe can be situated where the tortoise is, but ensuring it is out of reach of movement so as the tortoise does not tangle up in the lead. The reading face can be placed on top of the hibernating outer box. This way you will know the ambient temperature within the hibernation building which should be cold.  A brick out house is ideal. The ideal temperature as stated earlier should be 5 degrees Celsius, if it rises above six or drops below 4 then either additional insulation is required or moving the box to a more appropriate place.

Fridge Method

ONLY USE A FRIDGE THAT IS IN PERFECT WORKING ORDER. (If in doubt get it checked by a professional).

With our winters becoming warmer and unpredictable, more people are opting for the fridge method for hibernation.

Although it sounds daunting with correct and controlled measures it serves very well.

Once the wind down process has taken place and the tortoise has cooled right down then it can be transferred to a hibernating box with adequate substrate. It is then placed in the refrigerator that has been running for several weeks checking for temperature gradients and reliability. If you choose the fridge method then you must run it prior to using it to make sure it is perfectly safe and that temperatures are correct. 5 DEGREES CELSIUS.

To stabilise a fridge from fluctuation bottles of water can be added to reduce airflow.

You can purchase digital thermometers with alarms that can be set to go off if temperatures fluctuate higher or lower than the desired safe max or min. You must open the refrigerator daily to allow oxygen exchange for several minutes.

Daily visual checks are advisable it saves lives.

Should you notice that your tortoise has urinated in its box then it needs to be brought out of hibernation immediately, if left it could lead to dehydration and subsequent fatality.

Natural Hibernation.

Adults that have been used to naturally hibernating over the years may continue to do so. However precautions should be taken to protect them from frost.

Adults generally wind down themselves. They naturally stop feeding when temperatures drop and naturally become more and more inactive as the colder weather progresses. However they still need to be kept at temperatures of 13c or above to allow stomach contents to pass through during the wind down period. Bathing in warm water is a must to prevent dehydration during hibernation.  The health check and jacksons ratio must be carried out. Once you notice that your tortoise has found its hibernation place then it is imperative that you make sure it is protected from the elements. It is advisable to place some form of insulating material over the tortoise and surrounding area to prevent the frost from gaining contact. Frost can cause blindness and internal organ damage. Also consider flooding from heavy rains so try to encourage hibernating areas on higher grounds. There is a risk of predators so building a secured area around the tortoises chosen spot will prevent predator attack.

Young tortoises should be hibernated from 8-10 weeks providing their health and weight allows this. Adults should not hibernate for more than 16 weeks max. If weight checks are carried out, then you will know if your tortoise is safe to continue in hibernation or if you need to awaken them early.

Always be prepared. If a tortoise has to be brought out of hibernation early due to health reasons you will need adequate housing. Make sure you have indoor housing and heat (basking lamp) and UVB lighting accessible. This will save the panic for the worst case scenario.

I hope you have found this information helpful, but if there are any concerns please do not hesitate to contact us.