A. C. Highfield
This article is a brief guide to how to handle some very common problems that arise in autumn during the period when tortoises are preparing for hibernation (brumation) or shortly afterwards. It includes quite a lot of links to far more detailed articles on this website that cover certain aspects in much greater detail. Just click these to read them.
When mild weather is experienced in the autum, this causes many tortoise keepers serious concern, as animals that would normally already be in hibernation (brumation) are instead active and continuing to feed, or are in a 'mid-way' condition, neither hibernating nor feeding. Such a state, if maintained over a long period, can result in a steady loss of weight, to the point where should it (finally) turn cold enough to induce hibernation, they may no longer of sufficient weight to survive.
There are a number of scenarios keepers need to consider:
1) The tortoise is still feeding
If the tortoise is still feeding, it is vitally important that even if the weather changes and becomes cold enough for hibernation (50 F or 10 C) a period of fasting (non-feeding) MUST occur before the tortoise is placed in hibernation. The exact timescale required will depend upon several factors including the size of the tortoise (large animals require more fasting time than small animals), and ambient temperature: higher temperatures accelerate digestive function while lower temperatures slow the time taken to digest food in the upper digestive tract.
There is no ‘absolute’ timescale for this, but as a general guide only, at 65 degrees F or approximately 15 degrees C a medium sized tortoise will need about 3 weeks fasting time before it is safe to place it in hibernation. A small tortoise may require as little as 2 weeks at the same temperature, a larger animal may need as much as a month.
PLACING A TORTOISE FROM A WARM ENVIRONMENT WHERE IT HAS BEEN FEEDING IMMEDIATELY INTO AN ENVIRONMENT WHERE TEMPERATURES ARE 10 DEGREES C, or 50 DEGREES F. IS EXTREMELY DANGEROUS AND MAY RESULT IN DEATH.
A suitable fasting period at ‘intermediate’ temperatures is therefore vital. See ‘Safer Hibernation & Your Tortoise’ for full details.
Conditions for feeding
It is important to realise that tortoises only feed under certain conditions; in order to feed they need adequate light and radiant heat. In the wild, the warm Mediterranean sun provides both. In northern europe weather conditions are very different. In the wild, most tortoises have two 'feeding peaks', one in the spring and again in the autumn - summer is often too hot, and in many localities tortoises do not emerge to feed for days or weeks on end. The UK and northern European pattern is very different, with the spring often slow to start, the summer relatively mild and autumn cold and prolonged. Here, peak feeding occurs in mid-summer.
Therefore, do not worry if your tortoise has stopped eating after late summer or early autumn. If it appears to be free of health problems and is of adequate weight then there is probably nothing physically wrong.
Even when feeding has stopped, it is very important to continue to offer water to drink regularly as dehydration in tortoises can have serious implications.
If the weather is very poor in mid or late summer, then the tortoise may stop feeding too soon, however - if this looks like happening, you need to provide extra light and warmth to encourage continued feeding for a while longer. The further north you are situated, the more often this problem occurs.
Extended periods of very dull, cold weather can cause serious problems for tortoises. It may be necessary to provide extra light at heat at such times.
We suggest using indoor 'basking pens', or outdoor greenhouse-type accommodation where this is a problem. The process is the same as for overwintering. The main thing is to detect the problem early - it's too late to do anything about it after September. By then, the 'winding down' process will be well advanced. If a tortoise is underweight at this stage you will not be able to hibernate it safely, but must overwinter it in warm, light conditions indoors where it can continue to feed as described in the above linked article.
So, in general, a slow wind-down followed by a complete cessation of feeding is perfectly normal, but your tortoise MUST be of adequate weight by EARLY AUTUMN. You cannot 'boost' its weight by force feeding or by any other means after mid-summer.
To summarise:
DO NOT attempt to feed a tortoise immediately prior to hibernation as if you hibernate it whilst the upper digestive tract contains food it is in serious danger. Tortoises need a fasting period before hibernating.
DO REMEMBER that small tortoises (there are several geographical races, or 'varieties' of Mediterranean tortoise) are not able to withstand a long hibernation. These tortoises will require extra care - large tortoises are much better equipped to withstand longer hibernation (brumation) periods. Ineed, not all hibernate routinely at all (for example, Tunisian tortoises and Egyptian tortoises). Always be certain of the exact species your tortoise is, as this is critical to providing the correct diet and environmental care.
2) The house is too warm – everywhere else is too cold!
This is a common problem. The only viable answer in such cases is to resort to the refrigerator hibernation. This is not as scary as it sounds! With correct set-up it is a very safe and effective method, and completely overcomes the (serious) problem of fluctuating temperatures. We have some excellent articles describing how to achieve this in our online library.
Q&A
My tortoise has always hibernated in a box in the attic, but this year keeps waking up. What can I do?
The attic is clearly too warm. In this case, we would recommend refrigerator hibernation. Attics are in any event, along with garden sheds, a very high risk location for hibernation, especially during a sudden, unexpected 'cold snap', where freezing can occur in just a few hours.
Will it be a shock for my tortoise to suddenly change to a new method of hibernation?
No. Not at all. If the temperature is correct, it will hibernate perfectly safely.
They are predicting a warm autumn and then a very cold January. How might this affect hibernation?
This is a very dangerous combination. Animals may have lost significant weight prior to temperatures finally falling, and any severe freeze-up poses major risk of frost damage occurring. Monitor temperatures carefully (daily) and check weight regularly. Use the Jackson Ratio chart and measure carefully. In times of extreme low temperature move the tortoise to a safe (above freezing) environment as a matter of urgency. Even a few hours of sub-zero exposure can result in blindness or death.
My tortoise is 50 years old. I’ve usually put him away for hibernation by now but because of the warm autumn he’s still awake in box after a week. What should I do?
Check his weight carefully and monitor closely. Offer soaks and drinks every few days to avoid the risk of dehydration. Handling them carefully causes no problems. Going without food, even for a few weeks will not hurt provided he is a good weight and is well hydrated. Do not re-start feeding as that will re-set the clock on the fasting period. If you do decide to restart feeding, because of weight loss, for example, you may need to look then at overwintering. It is not possible to give exact time-frames for any of this, as there are many variables. The size and weight of the tortoise, the precise ambient temperatures, etc. You just have to monitor things and take decisions based upon your observations. Make sure you are completely familiar with all of the advice in our 'Safer Hibernation & Your Tortoise' guide.
Is moving a tortoise in hibernation dangerous?
No. It causes no problems whatsoever.
What if I cannot arrange for a ‘fridge and my house or garage is still too warm?
The only safe option is to OVERWINTER, meaning keeping the tortoise awake and feeding throughout the winter period. To do this you must provide adequate light and heat. For full instructions, click this link.
Can I hibernate my tortoise in my kitchen ‘fridge?
Not if you intend to use it for food at the same time. You should not mix animals and foodstuffs due to the potential for transmitting disease.
Would one of those small ‘drinks refrigerators’ be OK?
Some work, some don’t. Unfortunately, without testing them for temperature stability it is impossible to say. On the whole, a larger refrigerator will tend to give best overall temperature stability and accuracy. Again, see some of our separate articles on this subject.
My tortoise did have a short hibernation but woke up early. Should I keep it up now?
In general, yes. This is usually the safest course. It will need adequate light, heat and a suitable diet. See our 'Winter Feeding Guide' for some ideas.
My tortoise does not appear well after waking from hibernation, what should I do? I read online about 'post hibernation anorexia', could this be what is wrong?
Find a specialist vet without delay. Don't hesitate, but get professional help. This article explains some of the problems that might be involved. They require an accurate diagnosis followed by appropriate treatment. Don't guess.
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