Hibernaculum construction

[Bri]

How do people make their hibernaculums ? Just trying to get an idea of the variety of designs. I've considered hibernating my tortoises outside next year and want to build something in their side of the garden that is suitable.

Essentially it has to be warm (i.e. above freezing), dry and well drained. I've considered using a polystyrene box buried about 10 inches underground (measured from the top of the lid) but was worried about access to clean it or in case of emergency.

What would the box be lined with (?? hay or stray ?) ? Does it need to be lined with anything ?

How would you make a tunnel down to the box ? How would you prevent it collapsing ?

How would you prevent water flowing down the tunnel into the box ? I like the idea Killian has used with the entrance to his hibernacula with the rock slabs forming a cave structure, nice idea and looks very good. The green house would also overcome the problem of water getting into the box.

[willj]

for my hibernacular i dug a hole, put gravel at the bottom, then I put the lining of the viviarium over that, the lining is netting so as to allow water to escape. then I put another layer of gravel, followed by dry leaves, then wood chippings, then logs and rocks securely placed to give hiding spots, then another layer of leaves followed by the soil, I had two pipes at a gental gradient one going into the coldframe, one into the outdoor run, to stop excess water going in the pipes went up then down, and I placed a slate to make a natural "cave" enterance.

[phil]

bri, they do make land drainage pipe in sufficiently large diameters to allow passage for tortoises. the type with either slots or holes. if completely encased in coarse chippings very little water should reach the hibernacula if set on a shallow gradient. i've not actually tried this but it should work and i do intend to give it a go. also this type of pipe, although plastic, is ribbed in design and would allow tortoises to get a good grip on their way in and out

[Killian]

I am no expert on tortoises but i wouldnt imagine a hibernaculum to be suitable for them. I think a wooden box in the garage is the best idea, they are too valuable to take risks with. I think anyway! maybe others will disagree. do they hibernate under ground in the wild?

[willj]

yeah they do, they burrow in sandy soil, or at least according to Gerald Durrell anyway

[Bri]

I know of several people who allow their torts to hibernate naturally outside over Winter. One friend puts down 1 ft of straw with perspex sheeting over that to keep it dry. The tortoises burrow into it and move deeper in the colder it gets.
Mediterranean torts like Hermann's do hibernate in the wild.
The box in the garage method is frowned upon by the likes of the Tortoise Trust. It is too prone to problems caused by temperature fluctuation. They tend to recommend the fridge method which is more stable with regards to temp.

[Bri]

If the box is buried quite a way down, say over 1 ft, and the pipe is at quite a shallow angle on the ascent to the surface doesn't that mean the pipe is going to be quite a length i.e. several feet ?? Or is my geometry rustier than I thought ?