Black Guillemot
Cepphus grylle
The black guillemot is a medium-sized bird with adults normally 30 to 32 centimetres (12 to 12+1⁄2 inches) in length and with wingspans of 52 to 58 cm (20+1⁄2 to 23 in). The bodyweight can range from 300 to 460 grams (10+1⁄2 to 16 ounces). Adults have both summer and winter plumage and there is no sexual difference in this that can be identified in the field. The English common name "Black Guillemot" references their strikingly black breeding summer plumage which is totally black except for a large white patch on the upper side of their wings.
ID text from Wikipedia, CC BY-SA 4.0
Razorbill
Alca torda
The razorbill has a white belly and a black head, neck, back, and feet during the breeding season. A thin white line also extends from the eyes to the end of the bill. Its head is darker than that of a common murre. During the non-breeding season, the throat and face behind the eye become white, and the white line on the face and bill becomes less prominent. The bill is black, deep and laterally compressed, with a blunt end. It has several vertical grooves or furrows near the curved tip, one of them adorned with a white, broken vertical line.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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