The Wind Up

[Kirkie]

I’d like to share with you a method I’ve been using for bringing Hermanns tortoises out of hibernation for the last two years.

From mid September I bring my tortoises indoors, into large table type setups installed in my loft. This setup allows an improved temperature and a chance for me to extend the tortoises season but a few weeks either end each year. The tables have full heat/light rigs, the ambient temperature without heating remains a few degrees Centigrade above the outdoor temperature. As the weather turns colder in November I begin allowing the tortoises to wind themselves down by shortening “day” length and temperatures. The tables are all furnished with an insulated wooden box which has a thermostatically controlled tubular heater. The substrate in the boxes is a deep compost with some sections of curved cork bark. I use this to control night time temperatures and place the tortoises in these boxes at the end of each day. The thermostats have a day/night setting (Lucky Reptile Thermocontrol Pro II) so I am still able to give the tortoises a temperature boost in the mornings. I gradually dial down the day/night temperatures via the thermostat until eventually I leave the lights off and the tortoises enter a state of hibernation. This is completed by the end of November. By this time the tortoises are well dug into the compost substrate, usually under a piece of cork bark. The boxes have an entrance hole which is blocked. The thermostat is set to only activate the haters should the temperature fall below 4C. Due to the insulation of the boxes I’ve found that even if the odd sunny winter day takes the ambient temperature above 4C, the boxes remain stable.

During the last week of January I began programming the thermostats to increase the box temperatures by a couple of degrees day and night. The entrances were reopened and after a few days, with the box temperatures of around 12C during the day, tortoises began to emerge and the main table lights were switched on, allowing them to bask. The tortoises have exited the boxes in fine condition, I have had tortoises walk out of the box and begin eating immediately. They barely lost any weight between them. The humidity in the loft is a close reflection of conditions outside and has been between 60 and 80% through the winter. The tubular heaters do have a slight drying effect on the compost substrate but are so infrequently in operation during the hibernation period as to require nothing more than an occasion mist spray to bring the humidity back up.

I’m finding this a good way to reintroduce tortoises to activity, it’s probably close to the experience of tortoises hibernated in greenhouses but gives me total control over the environmental factor and the duration of the hibernation.

I was asked if this method could be appropriated for the fridge method of hibernation, the thermostat on the fridge gradually increased. It’s not something I’ve tried, my only real concern would be that the fridge is a sealed environment, As the temperature increases a tortoises respiration rate and oxygen requirement would increase so the air would need regular refreshing if it’s a large tortoise, small fridge or a number of tortoises in a fridge.

I’ve never really liked the old adage of bring them out of hibernation, warm room, then lamps. In nature the temperature increase is gradual. I’m aware of the supposed release of glycogen released upon exit for hibernation, boosting the tortoise enough to get it active. I can see the purpose of glycogen use at low temperatures, during hibernation, as the tortoise is unable to utilise fats at extreme low temperature and switches to simple carbohydrates but I don’t see evidence of a one off release. There are multiple accounts of a semi active behaviour in the wild as early as February, these tortoises are able to cope with a return to colder conditions and still emerge again.

Thoughts and comments welcome.

[justmeandmytortoise]

Thanks Dave

I always wonder what they do in the wild if the weather returns to another cold snap. Here we would keep them up, but in the wild they would dig back down again ...

[EJ]

in the California desert there are occasional warm snaps in the winter. The reptiles do come out. When the cold returns they go back down. In many cases this can occur in a single days time.

This is why I say hibernation is an adaptation and not a requriement.

[Kirkie]

Hi Wendy,

It must happen but the difference between our weather and mainland Europe is that the dips are rarer. Once the temps go up they tend to steadily increase. For example, This is 4 years of data from Sardinia, a region that still harbours a population of T. H. Hermanni.

http://www.knowital.com/weather/sardinia/

Wolfgang W has a theory that these breaks from hibernation in favourable conditions allow the tortoise to restart the metabolism, flush the system so theoretically if the tortoise returns to hibernation the levels of waste products in the body are low.*

[EJ]

Adaptation...

[Kirkie]

I don't disagree with you Ed. Its a very good adaptation, a brilliant solution.

[justmeandmytortoise]

Originally Posted by Kirkie

Hi Wendy,

It must happen but the difference between our weather and mainland Europe is that the dips are rarer. Once the temps go up they tend to steadily increase. For example, This is 4 years of data from Sardinia, a region that still harbours a population of T. H. Hermanni.

http://www.knowital.com/weather/sardinia/

Wolfgang W has a theory that these breaks from hibernation in favourable conditions allow the tortoise to restart the metabolism, flush the system so theoretically if the tortoise returns to hibernation the levels of waste products in the body are low.*

Thanks Dave

[richardb]

Kirkie i think you method sounds very good and replicates nature. I too have never liked the idea of my spurs going straight from hibernation to being wide awake and always like to bring them round gradually.

[Bindi]

the temps 10" under the soil in my greenhouse were up to 7.8 degrees C this morning at 6.45 am when it was 2degrees above ground. That's the highest so far, it's slowly creeping up. I'm hoping for an emergance by about the end of the month but will be intereting to see

[jamestaylor18]

My horsefields are currently hibernated in the fridge at the moment. They have been down for 4 weeks on sunday so doing well so far with no weight loss at all! Im planning for 8 weeks if possible and provided everything goes well.

Im a bit concerned about the wind back up after reading Jemmas post earlier in the week. My plan will be to put them both back into their viv with no lights on at about 8am (temp is usally around 10-15 deg c).
Once they are awake and a warmed to room temp (hopefully after a couple of hours!) i will turn on my uv strip with alone usually takes my viv temp to 20 deg c.
Once they are nicely warmed ill put on my basking spot light and get the hot side upto about 30 deg c. Given them a few hours at that then given them a nice warm bath! Due to having a lot going on the first day of winding up i probably wont feed them until the day after, just because the chance of them eating something anyway is pretty slim.

How does this sound to everyone?