Bannerman's shearwater is a seabird in the family Procellariidae formerly considered conspecific with Audubon's shearwater.
Region
Northwest Pacific
Typical Environment
Breeds on a few small, steep islands of the Ogasawara (Bonin) archipelago, nesting in burrows and crevices on vegetated slopes and sea cliffs. Outside the breeding season it disperses over pelagic waters of the Northwest Pacific, often associated with productive currents such as the Kuroshio. At sea it uses offshore and oceanic habitats well away from continental coasts. Colonies are typically free of large terrestrial predators and with limited human disturbance.
Altitude Range
Sea level to 300 m
Climate Zone
Subtropical
Ease of Keeping
Beginner friendly: 1/5
Bannerman's shearwater is a small, nocturnal-breeding tubenose that nests in burrows or rock crevices on remote Japanese islands. It was formerly treated within the Audubon's shearwater complex but is now regarded as distinct. Like many island-nesting seabirds, it is highly vulnerable to invasive predators and light pollution. At sea it spends most of its life far from land, shearing low over waves in strong winds.
Temperament
pelagic and wary
Flight Pattern
low, stiff-winged shearing over waves with rapid flaps and short glides
Social Behavior
Nests in small colonies, with pairs excavating or reusing burrows and rock crevices. Largely nocturnal at colonies to avoid predation, arriving after dusk and departing before dawn. Pairs are typically monogamous, laying a single egg that both adults incubate and later feed by regurgitation.
Migratory Pattern
Seasonal migrant
Song Description
At colonies gives soft, wailing trills and chatter-like calls at night, often exchanged in duets between mates. Generally silent while at sea.
Plumage
Small shearwater with dark brown to blackish upperparts and clean white underparts with a fairly sharp demarcation along the sides. Underwings show a white panel with a darker border and tips. Feathers are sleek and water-resistant, aiding prolonged pelagic flight.
Diet
Feeds mainly on small fish, squid, and other cephalopods, with occasional crustaceans. Captures prey by surface-seizing and short pursuit-dives, often in association with predatory fish driving prey to the surface. May forage at night on vertically migrating organisms. Will sometimes gather in loose feeding flocks where prey is abundant.
Preferred Environment
Open ocean and offshore waters, particularly along current edges, upwellings, and shelf breaks. Foraging often occurs near the breeding archipelago but extends widely over pelagic waters when not breeding.
