Adult Rooks are easy to identify thanks to the bare, greyish-white skin around the base of their bill. The rest of their plumage is all black.
A juvenile Rook, however, is similar to a Carrion Crow as it doesn't develop the bare bill-base until its second calendar year. If you're not sure, look for the Rook's characteristic flat forehead, peaked crown, ruffled drooping belly feathers and feathered thighs.
Rooks also have a straighter, more pointed bill, unlike the Carrion Crow's thicker, blunter and more curved bill.
Corvid Identification Video
Watch the BTO Rook Identification video to help you tell apart a Rook from a Crow.
Find out more about Rooks
You can find out more about Rooks, including their breeding behaviour and distribution, by having a look at the BTO's July 'Bird of the Month' feature.