The two Fulmars are closely related seabirds occupying the same niche in different oceans. The Northern Fulmar, or just Fulmar lives the north Atlantic and north Pacific, whereas the Southern Fulmar is, as its name implies, a bird of the southern oceans. These birds look superficially like gulls, but are unrelated, and are in fact petrels.
Both species breed on cliffs, laying a single white egg. Unlike many small to medium birds in the Procellariiformes, they are neither nocturnal breeders, nor do they use burrows. The chicks can eject an evil smelling oil several feet, which repels unwanted visitors. It will matt the plumage of avian predators, and can lead to their death.
They are highly pelagic outside the breeding season, like most tubenoses, feeding on fish, oil or offal.
Like other petrels, their walking ability is limited, but they are strong fliers, with a stiff wing action quite unlike the gulls. They look bull-necked compared to gulls, and have short stubby bills.
The northern species is grey and white, the southern is a paler bird with dark wing tips.
The range of these species increased greatly last century due to the availability of fish offal from commercial fleets, but may contract because of less food from this source and climatic change.