Hi Francine
The little hog doesn’t need to double in weight, the minimum recommended weight to survive hibernation is 450g. Although, hibernation is a difficult time for hogs and not all will survive regardless of their weight going into hibernation.
http://www.britishhedgehogs.org.uk/pdf/Hibernation-Weight.pdf
But at this stage, if you are feeding and the little one is regularly turning up for food and is otherwise healthy, I would be inclined to leave it in the wild and keep an eye on it. They do tend to put on weight very quickly when they’re small. Some hoglets choose not to hibernate even if they are over 450g. I have had a couple here and they continued to visit in well sub-zero temperatures. If a hog doesn’t hibernate, just keep feeding and providing water.
Over-wintering in captivity is very stressful for hogs and not all of those will survive either. I think the hog there is better off staying in the wild if possible. Of course when it gets a bit later and hoglets are still very low weights, they are likely to need help, but it sounds as if the little one there has a good chance of putting on enough weight whilst staying in the wild.
Good luck. Hope all goes well with the hogs.
