The slender-billed prion or thin-billed prion, is a species of petrel, a seabird in the family Procellariidae. It is found in the southern oceans.
Region
Southern Ocean and Subantarctic Islands
Typical Environment
At sea it ranges widely across the Southern Ocean, most often in subantarctic and cool-temperate waters. It breeds colonially on remote, predator-poor subantarctic islands and then disperses over vast pelagic areas during the non-breeding season. Birds commonly forage along productive shelf edges, fronts, and upwelling zones where zooplankton is concentrated. The species spends the vast majority of its life far from land, coming ashore only to breed.
Altitude Range
Sea level to 100 m
Climate Zone
Temperate
Ease of Keeping
Beginner friendly: 1/5
The slender-billed prion is a small southern-ocean petrel recognized by its narrow bill equipped with comb-like lamellae for filtering tiny prey from the surface. Like other prions, it shows a distinctive dark 'M' pattern across the upperwings when seen in flight. It breeds in dense nocturnal colonies in burrows on subantarctic islands and disperses widely across the Southern Ocean outside the breeding season.
Thin-billed Prion (Pachyptila belcheri) in the Drake Passage
Thin-billed Prion (Pachyptila belcheri) in the Drake Passage
Pachyptila belcheri - MHNT
Temperament
social and active
Flight Pattern
short rapid wingbeats interspersed with low glides over waves
Social Behavior
Breeds in dense colonies, nesting in burrows or rock crevices. Pairs are largely monogamous and share incubation and chick-rearing duties. Colony attendance is mostly nocturnal, likely to reduce predation, and chicks are fed at intervals by returning adults.
Migratory Pattern
Seasonal migrant
Song Description
Mostly silent at sea, but at colonies gives soft trills, cooing, and chattering calls, mainly at night. Calls are used for mate recognition and territorial interactions around burrow entrances.
Plumage
Smooth blue-grey upperparts with a darker 'M' pattern across the back and upperwings; clean white underparts; narrow dark tail band.
Diet
Feeds primarily on small crustaceans such as copepods and krill, along with other zooplankton and occasional small fish or squid. Uses its fine, lamellae-edged bill to filter or seize prey at or just below the surface. Often associates with oceanic fronts and convergences where prey concentrates, and may feed in mixed-species flocks.
Preferred Environment
Pelagic waters over continental shelf edges, fronts, and upwelling zones with high plankton productivity. Typically forages close to the sea surface, sometimes dipping or pattering to pick prey.
