Their plumage molts to white and grayish-brown in winter. Hunting in the shallows of bays and banks, guillemots specialize on small fish hiding among rock and kelp reefs. Their massive head and bill are distinctive. At sea, they are often seen bobbing on the waves, their longish tail and bill angled skyward. Outside of the nesting season, pairs separate to forage at sea.
Individuals can live beyond twenty years.
On Stellwagen, razorbills may be the most commonly seen alcid from November through early spring. They have been seen with many sand lance held crosswise in the bill. During severe, offshore storms, flocks may be driven close to the coast but sightings of these birds on Stellwagen are sporadic at best. Using their stubby wings, puffins pursuit dive for bait fish, such as herring and sand lance. Their deep, laterally compressed bills allow parents to carry a mouthful of fish back to their chicks, hidden in burrows on quiet islands.