Cepphus

Cepphus is a small genus of seabirds in the auk family (Alcidae). It comprises three species commonly known as guillemots: the black guillemot (Cepphus grylle), the pigeon guillemot (Cepphus columba), and the spectacled guillemot (Cepphus carbo). Members of Cepphus are compact, medium-sized seabirds with short wings and stout bills, adapted for diving and pursuing prey underwater.

In plumage the species are distinct but share a similar body shape. The black guillemot is largely dark with a contrasting white wing patch visible in flight. The pigeon guillemot has a browner body with lighter underparts. The spectacled guillemot is dark with a distinctive pale eye-ring, giving it a “spectacled” appearance. Sexes are generally alike in size and plumage.

Cepphus species are found along northern oceans, breeding on rocky coasts and offshore islands of the North Atlantic and North Pacific. They are migratory or nomadic at sea, returning to coastal breeding sites during the breeding season. Typical habitats include cliffs, ledges, and crevices near productive feeding areas.

Behavior and diet: guillemots in this genus are adept divers, feeding mainly on small fish and crustaceans. They pursue prey underwater using their strong legs for propulsion and can stay submerged for extended periods. Nests are placed in crevices or on ledges on cliffs, often with a single egg; both parents participate in incubation and chick rearing.

Conservation status varies by species and region, with populations monitored due to climate and human-related impacts on marine ecosystems.