Courtsey Kenn Kaufman
Although the bulk of the world population breeds in Iceland, Razorbills are widely distributed throughout the North Atlantic. Colonies extend east through northern Europe and northwestern Russia. In the northwest Atlantic, Razorbills breed mainly in small colonies scattered from northwestern Greenland, south through the Atlantic provinces of Canada to Maine, where more than 400 pairs nest on at least six islands. Most Razorbills from North American colonies overwinter south of their breeding range in ice-free, coastal waters, favoring shoals in the outer Bay of Fundy and Gulf of Maine. In winter, Razorbills occur south to Long Island, New York, and New Jersey.
A legend for the range map to the right can be found here
Razorbills tend to forage in the cool, relatively shallow waters over offshore ledges and shoals. Colonies nest on islands or on mainland cliffs and rocky shorelines.
Excellent divers that feed mainly on schooling fish, Razorbills typically feed at ocean depths of 30 to 60 feet, but are known to dive up to 400 feet. Several fish may be caught in a single dive; fish may also be stolen from other auks. In North America, important prey species vary with location and season, and include capelin, herring, and sand lance. In 2006, a study of razorbill diets in Maine found that Atlantic herring made up 60% of the diet, hake made up 27% of the diet, and other fish made up the remaining 13%. Crustaceans and marine worms are also important in adult diets, the former especially in winter.
Razorbills breed on rocky islands and steep, mainland cliffs. Most use nest sites that are at least partly enclosed, often in crevices among boulders or abandoned burrows of other species. As is typical of marine birds, Razorbills are colonial and mostly monogamous, with strong mate and nest-site fidelity, although females will sometimes mate with other males. Courtship displays include bill pointing, growling, bowing, and mutual preening. Breeding begins at four or five years of age; the nest is built by both parents. One, or rarely, two white to tan or greenish eggs marked with brown are incubated by both parents for about 35 days. Hatched nestlings receive several feedings daily, each consisting of several fish, which the adult bird holds crosswise in its bill while transporting them to the nest. After about 18 to 20 days in the nest, the male parent accompanies the chick to sea. At nest departure, the chick weighs less than one-third of its adult mass and has not yet begun to grow its large wing and tail feathers; chicks complete their maturation at sea. This unusual "intermediate" developmental strategy is similar to that of Common and Thick-billed murres, the Razorbill's closest living relatives.
Razorbills disperse widely after breeding, wintering far offshore from Newfoundland to southern New England, and rarely, as far south as Florida. European birds may winter as far south as northwest Africa. Winter distribution depends upon weather and food supply.