Hi,
If the little bun is not injured it is probably best just to release it as soon as you can, back to where it was found so it can find it's way home. (not in the road though!.. although I'm sure some would disagree
) They are totally independant at 4 weeks old as Mum would be having her next litter, and they venture out from the warren to graze at about 3 weeks. If it is quite skittish as you say, then it probably is of this age as they tend to have less fear of humans when they are younger. I'm sure it would be quite stressed if kept in a hutch for too long. If you are really unsure if it is old enough, could you get a picture of it?
Hope this helps.
