Ravens?

Given that I only saw my first ravens this year, I'm a bit hesitant to call these, especially as there were so many - over twenty in total.  The numbers suggest they're more likely to be rooks, but their behaviour was not rook-like, and while it was difficult to judge size, the impression I had was too large to be rooks.  (I thought "buzzard" initially when I saw the first bird, then they just kept coming ... )  They do seem to have the diamond tail shape of ravens.

I have a lot more photos, but none of them is any more helpful, I don't think.