I can't comment about wild buns.
My mixed breed was rescued fairly young, perhaps about 14 -15 weeks. I was so fascinated by him, I allowed him to make a mess at ground level of the kitchen. In particular he wanted to get an old bag of flour off a shelf with a retaining bar almost at ground level. When a shove didn't work he ripped it open with his back feet. Yep he got it off the shelf but also discovered that the flour on his feet gave him better grip on the vinyl floor. So I left a small heap for him - just like ballet dancers chalk their shoes. I think most buns are like this, but we have to spend a lot of time with them, & I suspect that like us their learning capacity is much greater when young.
The most remarkable aspect is the way he devised a communication system between us. I was discussing this with my vet yesterday. Unfortunately for her, he mainly tells her "I don't like that" in various degrees of magnitude, but he has his way of asking me to play, & even turn up the fire. I think that they are very highly intelligent, but tend not to be obedient unless they want to do it!!