humidity in hibernation

[Ozric]

Hi all.

I am concerned about the level of humidity during refridgerator hibernation. I believe that the weight loss of a tortoise in hibernation has a lot to do with the amount of humidity in its environment. Refridgerators tend to be dry because air at that temperature does not hold much water in it regardless of what efforts are made with bowls of water in the fridge - it won't evaoprate.

Therefore does it make sense for the substrate in which the tortoise is hibernated to be slightly damp? Clearly this cannot work when using newspaper or similar materials but if a soil and sand combination is used for hibernation it seems to me it makes sense for this to be slightly damp. I emphaisise slightly as a cold and wet tortoise is a bad situation obviously.

Would welcome views on this question. Also the measurement of the humidity becomes a problem because I believe that only the humidity of the air above the substrate can be measured with any accuracy. Again I would welcome thoughts on this.

I think Danny helped me last year by suggesting that a 60-70% humidity during fridge hibernation might be right for a Hermann but I was unable to achieve that level of humidity in my fridge. (Apologies to Danny if it was someone else!)

 

[GBtortoises]

I think you're absolutely correct about weight loss of a tortoise during hibernation. The colder air becomes the less humidity it holds.
I have experimented with a few things over the years: sphagnum moss, potting soil , leaf litter, all by themselves and as a mixture. I think they work fairly well, but the same problem arose each time, the air was still very dry, even with a few pans of water with sponges in them to act as wicks.
Another thing that I have tried is placing a small size humidifier in the refrigerator, (coincidently I just commented about the same humidfier in another catergory on this site today). It works very well, but the hibernation chamber needs to be up and running a few weeks in advance so that the humidifier can be tweaked and adjusted to the humiditiy level that you want. The drawback is that the humidifier needs constant filling. I've been thinking about attaching an outside line that is piped into the humidifier.

Just a quick observation: Some of my older, long term Hermann's spend the winter outdoors hibernating naturally (with some added insulation and weatherproofing added by me). Whenever I have checked on them just before and near the end of their hibernation, the immediate area surrounding them is somewhat damp. Not wet, but they usually have moisture on their shells.

 

[Ozric]

Thanks for those comments GB, we haven't solved it yet but my thinking seems about right. Its useful to know as well that your older hermanns have not been harmed by hibernating with a little moisture round about them.