Hibernation help

[Rednwhite1889]

I have a Hermman Tortoise approximately 7 years old. I took over looking after it from my wife’s sick nan.

This year I have read a lot about hibernation and which methods and build up etc. Approximately a week ago I placed tortoise into a fridge in its box. And have kept the temperature in and around 4-6 degrees.

Today I have opened the box to check on her and her head popped out and looked at me. I was a little surprised. I am quite new to all this. Is this normal, I assumed as she had been down at a cold temperature for just over a week that she would be nicely asleep?!

Any help or advice would be great.

Thanks

 

[JoesMum]

How certain are you that temperature is staying where you think?

Is this fridge the regular one used by you, because if so it gets warm every time you open the door. You really need a dedicated fridge for hibernation. You also need a digital min/max probe thermometer that lets you know the variation.

In my dedicated fridge, I had a variation of plus/minus 1C in the box with Joe even with opening the door once a day for a few seconds to change air.

Handling a hibernating tortoise should be like handling a house brick - no response. Maybe the legs extending, but no more.

You should have weighed your tortoise before hibernation and weight it monthly throughout. If weight loss approaches 10% the tortoise must be wakened.

In practice, Joe never lost anything close to 5%, let alone 10%, in his 42 hibernations. They shouldn’t if temperatures are correct.

 

[Gillian M]

A very wear welcome to the forum, @Rednwhite1889 .

Please post pics of your tort and her enclosure so as to enable us to help you more easily.

 

[WithLisa]

How did you prepare your tortoise?

You should have weighed your tortoise before hibernation and weight it monthly throughout. If weight loss approaches 10% the tortoise must be wakened.

Just wondering - have you ever heard about a case of significant weight loss as long as the tortoise is kept moist enough?

 

[JoesMum]

How did you prepare your tortoise?


Just wondering - have you ever heard about a case of significant weight loss as long as the tortoise is kept moist enough?

It’s not the moisture that seems to cause the problems. It’s the temperature. People thinking their tort is hibernating when it isn’t.

It’s more common to have issues in the box method... people box them up and leave them
In the garage for 4 months without realising that the temperatures are fluctuating. The tortoise doesn’t go dormant properly and burns precious calories shuffling round the box on warmer days.

The same would happen in a fridge that’s shared with your food. You are in and out constantly so temperatures don’t stay low enough for any length of time.

 

[Rednwhite1889]

Thank you for the replies.

preparation wise I spent a few weeks winding her down. Stopped feeding and have daily baths etc to make sure she was all cleared out and hydrated and started lowering temperature for it.

In terms of fridge.

She is in a mini fridge with nothing else and solely for her. I have placed her in a plastic box slightly bigger than her, and drilled holes for air flow. I have placed temperate probe into the box and this is what is registering between 4-6 degrees.

She was weighed fully in lead up, on the Jackson ratio she came as a perfect weight for hibernating.

I am very new to this but determined to get this right so your help is appreciated.

 

[JoesMum]

What weight was she before hibernation?

 

[Rednwhite1889]

1389grams

 

[JoesMum]

That’s a good weight

 

[Markw84]

It’s not the moisture that seems to cause the problems. It’s the temperature. People thinking their tort is hibernating when it isn’t.

It’s more common to have issues in the box method... people box them up and leave them
In the garage for 4 months without realising that the temperatures are fluctuating. The tortoise doesn’t go dormant properly and burns precious calories shuffling round the box on warmer days.

The same would happen in a fridge that’s shared with your food. You are in and out constantly so temperatures don’t stay low enough for any length of time.

Just a note about brumation...

I personally am not a stickler on calling it hibernation or brumation. Technically a tortoise is indeed hibernating. But brumation is a term first created in the 1970's, if my memory serves me, as reptiles hibernate differently than mammal do. So the term "brumation" was proposed and it seems most scientists have now accepted it as it does indicate some important differences in reptile "hibernation". So that brings me to my point-

A brumating reptile has very little fat stores and instead uses increases glycogen levels as their energy source during brumation. They do not "store fat" for the winter as a mammal does. They add increased levels of glycogen that is stored in the bloodstream and cells throughout the body. (This also actually serves as a sort of antifreeze as well. The freezing point of the tissue is actually lowered which protects many aquatic species that hibernate where they can sometimes be exposed to temperatures slightly below freezing!!) So they do not lose any appreciable weight from body mass. Any weight loss is an indication of water / hydration loss. A brumating turtle or tortoise should normally have practically NO weight loss. If there is - it is an indication of them becoming dehydrated.

So another difference in brumation vs. hibernation, is that the animal does not really go into a deep, suspended animation style sleep. Brumating chelonians are actually semi-awake and will often have periods of some activity. For those in more moderate areas of the world where winter temps can often have days that get into the 50's or more, there will be periods of movement and even basking. In those cases they will often drink and replenish hydration. They do not eat, but a brumating reptile will drink - Another definitive distinction of brumation vs hibernation. The value of those who hibernate/brumate their tortoises in fridges, is that the temperature is controlled and not let to rise - so the loss of hydration is not a concern as metabolism is kept almost stopped at those constant low temperatures.

 

[MrMarg&me]

Wow thank you Mark for that lengthy explanation. It is very interesting to learn about brumation and why that term is chosen over hibernation. I attempted to explain to a Colorado reader why she could not allow her sulcata to have long periods of cold temps. But I obviously did not know enough to explain it correctly. I have learned valuable information on this site.