Probably crows, ravens are quite rare.
They will have chicks in the nest now, probably.
Until the chicks fledge, you'll see the parents going back and forth, and you'll probably see lots of white streaks on the ground. The chicks crap little globs, and the parents take them out of the nest and drop them on the ground as they fly off (so that the nest doesn't fill up with chick poo).
Can you get a view of the nest from a neighbour's house?