The Razorbill has white underparts and a black head, neck, back and feet during breeding season. A thin white line also extends from the eyes to the the bill. Its head is darker than that of a Common Murre. In the nonbreeding season, the throat and face behind the eye become white, and the white line on the face becomes less prominent. The thick black bill has a blunt end. It is large for an alcid and its weight ranges from 505 to 890 g. The female and male adults are very much alike, having only small differences such as wing length. This species has a horizontal stance and the tail feathers are slightly longer in the center in comparison to other alcids.
Habitat and Distribution
They are distributed across sub-arctic and boreal waters of the Atlantic. Their breeding habitat is islands, rocky shores and cliffs on northern Atlantic coasts, in eastern North America as far south as Maine, and from northwestern Russia to northern France. North American birds migrate offshore and south, ranging from the Labrador Sea south to the Grand Banks of Newfoundland to New England. Eurasian birds also winter at sea, with some moving south as far as the western Mediterranean.
Razorbills dive deep into the sea using their wings and their streamlined bodies to propel themselves toward their prey. While diving, they capture and swallow many schooling fish, such as Capelin, Sand lance, juvenile Cod, Sprats and Herring. They may also eat crustaceans and polychaetes.
Individuals only breed at 3-5 years of age. As pairs grow older they will occasionally skip a year of breeding. Nest sites are not immediately alongside the sea on open cliff ledges but at least 10 cm away, in crevices on cliffs or among boulders. Nests are usually confined among the rocks. Females lay a single egg per year. The egg is an ovoid-pyramoidal shape, ground in color and has dark brown blotches. Incubation occurs generally 48 hours after laying the egg.