guillemots

Guillemots are seabirds in the auk family, belonging to the genus Uria. The common name typically refers to two living species: the common guillemot (Uria aalge) and the thick-billed guillemot (Uria lomvia). They are part of the murre group, which is widespread along the coasts of the northern oceans and known for their cliff-nesting habits.

Guillemots are medium-sized, robust seabirds with compact bodies, short wings, and strong, pointed bills. They have dark upperparts and pale underparts, and during the breeding season they may show distinctive facial markings. They are skilled divers, using their wings to propel themselves underwater in search of prey. They nest on steep cliff ledges or rocky crevices, typically laying a single egg that is incubated by both parents.

Diet and foraging behavior center on fish and other marine prey. Guillemots forage by pursuit diving, often chasing schooling fish beneath the surface and occasionally taking crustaceans. They may travel long distances to find food and can form large breeding colonies on suitable coastal sites.

Distribution and habitat span the temperate and Arctic waters of the Northern Hemisphere. Common guillemots breed along the coasts of Europe and North America, while thick-billed guillemots breed in Arctic regions of the North Atlantic and North Pacific. Outside the breeding season, they are highly pelagic and widely dispersed at sea.

Conservation status varies by region and species, but threats include oil spills, entanglement in fisheries, habitat disturbance on breeding colonies, and climate-driven changes in prey availability. They are protected in many areas and monitored by regional wildlife programs, reflecting their value as an iconic northern seabird group.