New bird species - Raven

I know this is Raven country but I hadn't seen one until yesterday. It was the distinctive call that alerted me - it sounds like a double bass version of a woodpecker to me. The picture is poor but it was all I could do at short notice. The raven performed some aerial stunts above our fields before disappearing rapidly into the clouds. Strangely enough I was out walking later in the day and a couple of miles away I came across seven ravens - again confirmed by the calls. I hadn't appreciated that ravens flocked as I have only ever seen them in ones and twos before.