Well, the time has come to start thinking about hibernating your tortoises, for some of you, this will be routine... but for others it can be a nerve wracking time! I’m going to tell you about some myths, facts and truths regarding hibernation, backed up with evidence where possible. I will also share with you my experience of fridge hibernation. I had always hibernated my torts this way until last year when I decided that I wanted to give my torts a more natural environment all year round, so now they hibernate outdoors as nature intended (with a little help!). As I’m still very new to natural hibernation I shall leave that one to the experts!

Disclaimer!

Because I have only ever hibernated Hermanns, my advice/information is going to be based on them, that said most (if not all) breeds that hibernate would be able to be hibernated the same way. You should, however research your own breed as much as possible in case there are any differences. Please also note, that this is a guide based on MY experiences, and is for information only. I cannot be held accountable for any problems that occur during the hibernation of your own tortoise, you do so at your own risk!

So Why Hibernate?

In the wild animals live as mother nature intended. If we want to bring these animals into our homes we should try to mimic where possible their natural world. This includes hibernating some breeds of Tortoise.

Hibernation forms part of the natural cycle of the Hermanns Tortoise - in fact it is a vital factor for females as these may otherwise become infertile (Wegehaupt, 2009).

There is some evidence to suggest that hibernation allows the tortoise to live longer by allowing normal thyroid function (the gland that controls metabolism) (Girling, 2002)

Both of these books have good evidence for hibernating and are well worth reading (particulary Wegehaupts book)

Reason’s For Not Hibernating:

Obviously you know your tortoise(s) so ultimatly the desision on whether to hibernate or not lies with you. The main things you need to take into account are health & weight; Provided your tortoise has been eating healthily through the year and has gained weight and there is no visable evidence of ill health then there is no excuse but If there is any doubt then do not hibernate!

Your tortoise will benefit from it BUT there are some guidelines to follow!!!!! Failure to follow the guidelines will put your hibernating tortoise at risk.

* Ensure your tortoise has completed the ‘Wind Down’ period before hibernation.
* Ensure your tortoise is well hydrated.
* Check your tortoise’s weight against the Jackson Ratio or there is an alternative chart that I personally prefer that I found on the BCG. I have put it at the bottom of this post. Here's a link for it :
alternate-growth-chart-t1443.html
The JR is already on the forum and can be found here: jacksons-ratio-t8.html
* Make sure you have a decent fridge - this MUST be a LARDER fridge (the type that doesn't have a freezer compartment!) I have tried using the smaller drinks chiller fridges but found the temperature really fluctulates in these and they are hard to get a happy medium - you also need to be VERY careful as these can freeze if the room temperature drops too low - remember they are only chillers not fridges and there is no real control of the temperature!!! Trust me, there is no point cutting corners!!!! You are putting your tortoise at risk if you do You can get larder fridges for as little as £80 if you shop around....
* Make sure you get your fridge up and running at least a couple of weeks BEFORE you hibernate - this way you can get the temperatures settled. Use bottles of water to help stabalise the temps.

So, your tortoise is a good weight and is healthy.... the next step is to decide which method of hibernation you are going to use. As I’ve already mentioned I am only going to cover Fridge method here. Terry has done a excellent topic on the box method, and this can be found in the Hibernation section along with other members experiences. Julia has also done a good post on her experiences of fridge hibernation.

Here is an account from 2009 when I last hibernated my torts using the Fridge method. This is an actual 'diary' that I posted on another forum that I was a moderator on:

Posted 11 October 2009 - 02:34 PM
Ok, I'm going to start my wind-down at the beginning of November and hibernate at the beginning of December.

Between now and the beginning of November I will be reducing the torts food. I will also give them a 'dark' day once or twice a week.

This week, I will feed them every other day.

Their lights are on from 7.30am till 5.30pm.

Currently they are still active and eating although already they are all snuggled up asleep. They are definatley sleeping more now. Today they were all bathed and weighed. Here are their weights/lengths;

GRACE (F, '97) - W = 962g, L = 18cm
962 / 18 / 18 / 18 = 0.16 - Slightly light but her weight is very approx as scales are too small for her. She is otherwise fit & healthy.

TALLULAH (F, '99) - W = 736g, L= 16.5cm
736 / 16.5 / 16.5 / 16.6 = 0.16 - Same comments as Grace!

FRANK (M, '01) - W = 472g, L = 13.3cm
472 / 13.3 / 13.3 / 13.3 = 0.20 - Nice healthy weight.

ARCHIE (?M, '05) - W = 228g, L = 10.1cm
228 / 10.1 / 10.1 / 10.1 = 0.22 - Again, nice healthy weight.

TEEFA (?F, '07) - W = 154g, L = 9.3cm
154 / 9.3 / 9.3 / 9.3 = 0.19 - Nice and healthy.

All of them wee'd & poo'd during their baths and hadn't eaten since Friday. Both Grace & Tally are far too big for my scales and hang of the sides! So I am not concerned about their weigts at all. They all feel nice and heavy to hold. All 5 of them will be hibernated.

I will post again next week.

Posted 25 October 2009 - 04:02 PM
ok, just bathed and weighed my little ones, this time next week I will start starving them

GRACE - 1,002g = 0.17
TALLY - 766g = 0.17
FRANK - 511g = 0.21
ARCHIE - 244g = 0.23
TEEFA - 170g = 0.21

I'm really pleased with them as they have all put on weight over the last few weeks.

They are now on half their normal diet so will reduce right down again this week, I will also feed every other day. There lights will be on from 7am - 2pm (7hrs)
As this week goes on I will further reduce the amount of food they are having. The hours of daylight will stay the same.

The four weeks of starvation wind down will probably be done ;

week 1 - no food, 6 hours of heat/uv
week 2 - no food, 5 hours of heat/uv
week 3 - no food, 3 hours of heat/uv
final week - no food, 2 hours heat/uv reducing down to no heat/light provided no bowel movements.
The last couple of days I will move them into the utility room where hopefully with all heat turned of they will get used to the reduced temperature, finally resulting in them going in the fridge.

Their baths will be increased over the next couple of weeks and in the final week I will bath them everyday, their last bath will be the day before they go in the fridge.

Posted 01 November 2009 - 09:02 PM
My little ones had their last meal today, from tomorrow they will be 'starved' in prep for hibernation. We have today had a new little shelled one join the fold and he too will begin the hibernation process with my others
Their lights will be on from 8am - 2pm.

Weights:

Grace - 1001g (0.17)
Tally - 761g (0.17)
Frank - 462g (0.19)
Harry - 302g (0.26)
Archie - 227g (0.22)
Teefa - 159 (0.19)

Posted 22 November 2009 - 05:53 PM
Hi all, well we are on our last week now. Have just bathed and weighed the tortoises. Here are their current weights...

Grace - 809g
Tally - 675g
Frank - 435g
Harry - 282g
Archie - 217g
Teefa - 145g

The girls in particular have lost quite a bit of weight on wind down, I am still going to hibernate them as they have been well over the summer eating lots and healthy. All the others are above 0.18, yet these two come out as below 0.16!!!

This week, I will keep the lights off and bath every day, and all being well and no evidence of poo they will go in the fridge next weekend.

Posted 30 November 2009 - 10:50 PM
Torts on last few days now, unfortunatly had to put date back as Harry poo'd on Sunday!!!! They have really slowed down now. They are in my utility room and the temps are around the 13 - 14 degrees mark. I also had to go out and buy new fridge on Saturday as the other one was too small for 6 torts!!! So they are now the proud owners of a new supadooper fridge!

Bathing them every day now, and hoping to put them in fridge when I'm of Thursday afternoon.....lol! Watch this space!!!! Summits bound to go wrong!!!! Haven't weighed them this week if Im honest, but they are all fine and in good health. Will weigh them before they go in fridge.

Posted 06 December 2009 - 12:48 PM
That's it, have just finished putting my little ones to bed for the winter! God it's traumatic - as we speak Grace and Harry are franctly trying to climb out their boxes so have moved them on shelf below in the fridge where their boxes are wedged in so they cant climb out!!! Hopefully they will settle shortly????

They all had their last bath yesterday evening so hopefully will have enough reserves to see them through. They were all weighed before boxing them up. I have put them in their bedding they have in their table - a topsoil mix so hopefully they will snuggle down, they all have a piece of polystyline as a lid. Their boxes are the biscuit tubs for the larger ones, and ice cream tubs for the smaller ones. I will have a thermometer on each shelf. Currently only have one in their as needed to get fridge door shut so that the temps fall a bit!!! Later on when hopefully they have climatised I will add the other thermometers! (Thats if Grace & Harry haven't tunneled their way out by then!!!!)

Posted 05 January 2010 - 11:02 AM
Just weighed my little sleepy ones - thought I'd take advantage of a blooming cold morning before the heating kicked in!!

Grace, Tallulah & Frank have all remained the same - no weight loss at all!!!!

Harry has lost 2g - but this is his first ever hibernation (he's 5yrs +) and was very fidgety at the beginning!

Archie & Teefa, well, I think they must have sneaked in a midnight feast as they have both put on 1g each!!!!!

Another couple of months to go..........


So there you have it! Easy-peesy! They woke up none the worse for where in the March.

For those of you that want to use the alternitive formula, here it is in laymans terms!
I use a different method to the jackson ratio as the JR is more a guide and is based on an average tortoise, but all torts vary in shape and size and I find this other method works better, here's the formula:

Take the torts WEIGHT in GRAMS (eg 82g)

Then take their LENGTH in CENTIMETRES (eg 7.5cm)

DIVIDE (/) their WEIGHT by their LENGTH 3 times, eg 82 / 7.5 / 7.5 /7.5 = 0.19

Then using the table below you can work out if they are safe to hibernate;
< 0.16 = Underweight *DO NOT HIBERNATE*
0.17 - 0.18 = Light for hibernation *MONITER WEIGHT CLOSELY*
0.19 - 0.22 = Safe to hibernate
> 0.23 = Overweight *MONITOR WEIGHT*

Again this is only a guide but I find it more accurate than the JR (my opinion only!) I have to say that when I first hibernated Tallulah she was under 0.16 due to the fact she hadn't eaten for ages but was otherwise healthy so I went ahead and hibernated her anyway and she was fine. On average mine tend to be 0.19 - 0.21
I also use this method to guide me through the hibernation period. Providing they don't fall below 0.16 I leave them. You will find that they don't change an awful lot. I think they say to aim for no more than 1% total bodyweight per month.

Please be aware though that particulary the first couple of weeks they will lose more weight as they tend to move around a lot. I was told (but can't remember who by - think it was Danny from USA) that torts don't actually sleep all the time they are in hibernation and actually spend most of the time awake - so don't be suprised if you see little eyes pearing at you when you check them!!!! This is perfectlly normal!!!!

Posted 22 September 2009 - 08:57 PM
I do their weight using this method before windown;

here's Franks diary from winter 2007/2008 hibernation - his length was 11.5cms

Pre-wind down
24/09/07 - 0.20 (317g)
08/10/07 - 0.22 (344g)

Wind down - started 18/10/07
22/10/07 - 0.20 (314g)
30/10/07 - 0.20 (309g)
04/11/07 - 0.20 (306g)

Fridge - 7/11/07
@ 306g (0.20)

Woke up - 10/3/08
@ 293g (0.19)

Total weight loss - 13g

Here’s a photo of my lot in the fridge:


This was taken the year before when I used Ambiouse as the substrate. In 2009 I swapped to topsoil and had much better results as in they settled better and had less weight loss.