Fluttering shearwater: where and when to see them

The fluttering shearwater is a small seabird that breeds on islands around New Zealand and spends much of its life at sea. Its English name describes the rapid wingbeats that interrupt low glides above the surface. Large feeding gatherings may be visible from coastal headlands or vessel decks. Nesting colonies are vulnerable to introduced mammals, making predator-free islands and effective biosecurity particularly important to the species' continued breeding success.

Size

31–37 cm long

Weight

225–425 g

Lifespan

Not reliably established

Status

Least Concern

Fluttering shearwaters often travel and feed in groups, sometimes forming conspicuous streams of birds close to the coast. Their flight alternates quick flapping with short glides, usually low over the waves. Breeding adults return to burrow colonies mainly after dark, reducing exposure to daytime predators. Outside the breeding season, some birds disperse widely, including across the Tasman Sea, while others remain in New Zealand coastal waters. Courtship rituals include mutual preening and calling at the burrow site, reinforcing pair bonds. During foraging, they often associate with other seabird species like gulls and terns, benefiting from shared information on prey location. Their crepuscular and nocturnal return to colonies is a strong anti-predator strategy, especially against aerial hunters.

• Its breeding range is confined to New Zealand.
• A pair normally lays a single egg per breeding attempt.
• Adults usually visit their nesting burrows at night.
• Some individuals cross the Tasman Sea outside the breeding season.

Birds can occur around New Zealand throughout the year, with spring and summer coinciding with breeding attendance at northern and central colonies. Coastal visibility depends heavily on wind, sea conditions and prey distribution. Autumn and winter movements can also produce substantial coastal gatherings. Peak breeding activity, including chick rearing, occurs from late spring through summer, offering excellent opportunities to observe adults returning to colonies. While year-round residents, their distribution and density near the coast can vary significantly with oceanographic conditions. Winter months can still yield large flocks, particularly in areas with consistent food supplies.

At sea, this shearwater favors coastal and continental-shelf waters, including straits, bays and productive waters around islands. Breeding takes place in burrows on offshore islands, usually where introduced predators are absent or controlled. Nesting habitat is not necessarily open to public access. Though generally coastal, some birds may range further offshore, especially during non-breeding periods. These shearwaters demonstrate strong fidelity to their breeding sites, often returning to the same burrow year after year. They prefer islands with dense vegetation cover, which helps protect burrows from erosion and predators.

Small schooling fish and marine crustaceans are the principal foods. Birds gather where prey becomes concentrated near the surface, sometimes alongside other seabirds. Feeding opportunities shift with currents and prey movements, so a productive headland one day may be quiet the next. They employ a 'surface-feeding' technique, snatching prey from just below the water's surface while swimming or performing shallow dips. While small fish and crustaceans are primary, they will also opportunistically consume squid when available. Their feeding habits are efficient, allowing them to quickly exploit ephemeral prey aggregations.

Common name

Fluttering shearwater

Scientific name

Puffinus gavia

Animal group

Birds

Size

31–37 cm long

Weight

225–425 g

Lifespan

Not reliably established

Status

Least Concern

Identification

Compared with Hutton's shearwater, it usually shows a cleaner white throat and underwing, though distant birds can be difficult to separate reliably. Key distinguishing features include a diagnostic brownish-black upper side contrasted with a clean white underside, including the flanks. Their relatively small size and rapid wing beats compared to larger shearwater species can also aid identification. Note the short, stout bill which is typical for a surface-feeding seabird.