Rooks (above left) are easily distinguished from the similar-sized carrion crows (Corvus corone) (right) by their grey beaks and grey patch of skin on the face.
The crows tend to appear in much smaller numbers, often ones and twos. They are very hard to photograph because of the uniform blackness of their plumage, from which it is very difficult to pick out clear features.
Magpies (Pica pica) do a very good impression of being always dressed for dimmer, but since dinner is likely to include small birds and nestlings they are not often welcome guests. They are rumoured to harbour larcenous intentions as well. From a bird photographer's point of view however they do offer at least the potential for better compositions than their all-black relatives.
There is at least one pair of ravens (Corvus corax) in the neighbourhood, but so far I have seen them only in flight and photographed them poorly. The easiest distinguishing features of this bird are the wedge shaped tail and 'cronk' call note.
I have mentioned in an earlier post how good the crow family are at mobbing buzzards. Usually the aggrieved raptor will just lumber stolidly away, doing its best to appear unconcerned. Recently however I observed an interesting variant. The buzzard simply climbed in a spiral until it exceeded the operational ceiling of the mob, all of whom promptly dropped away and descended again to the tree tops.