Could there ever be wild tortoises in the UK?
 

While I was away on a trip in Devon last week, while walking on Dartmoor and seeing some habitats that looked ideal, with global warming and increasing ambient air temperatures, could a wild population of tortoises ever sustain itself at these latitudes?

Would they ever get enough intensity and duration of sunlight? Would the soil ever be warm enough to incubate eggs and maintain a sustainable population? Would they survive the winters if air temperatures were higher? Would predators (and humans) completely destroy them?

Personally I think the tortoises have half a chance, but as for eggs then no, as my tortoises lay eggs in my lawn and I leave them there. No signs what so ever of them surviving as temps are not high enough for long enough to allow eggs to hatch. Maybe in another 30yrs it might be possible:0)

I have heard of lots of lost tortoises in fields or gardens coming up to the surface after hibernation , even after snow. So we know they can survive the climate. it is a conundrum because of the eggs - though this year may be different but maybe they evolve so temps don't have to be so high...or are all males ! goodness think I saw a miss B bardou film similar. 200, million years would suggest they find a way even if born in sunnier clims and swim across on plastic, CB

So to experiment you would need to release a large mixed group all the same age so they would terminate life roughly at the same age. So then you would need to live long enough to record all your findings. And then as Claire says any eggs laid would possibly be male due to cooler temps at hatching.
So eventually they will die out due to no females to breed with. So my conclusion is until we warm up they would survive but die out eventually due to not being able to procreate.

My husbands granny , in deepest Cornwall , used to have a large tortoise,( No one can remember what sort it was ) That roamed freely in 4 acres of garden, every now and again it would appear. It hibernated itself and fed itself, and after many years, it stopped appearing. I think it’s very unlikely they could incubate eggs in the wild even down in Cornwall .

I've said this on here before but we had one that escaped and was found five years later still doing fine. That was in the 60's when we had real winters. Their names were painted on their shells. It had also managed to get across a fairly wide and deep river. A bit of a difference between that and surviving long term permanently though