Ground Scratching

My Border Collie has started this big grass-scratching performance after he goes to the bathroom. I heard that this is some kind of male dominance thing. I thought they liked to have their smell everywhere - why would they try to bury it like a cat - or is that not what they are doing?

They are not trying to bury it. If they wished to bury it, they would do so. The scratching does not even come close to doing this.

Wolves do this in the wild. The two explanations put forth to explain this behavior are: 1) they are adding an additional scent to the area, marking the region for passersby, through the scent glands on the soles of their feet (ever smell the popcorn smell on their feet?) or 2) disturbing the earth to provide a visual marking of the area. Take your pick.