Sooty shearwater: where and when to see them

The sooty shearwater is a dark, long-winged seabird whose annual movements link New Zealand breeding islands with distant North Pacific feeding grounds. Known in New Zealand as tītī, it has deep cultural importance, including customary harvest traditions associated with southern breeding islands. Its apparently effortless passage above waves conceals an energetically demanding life. Birds return to land to breed in burrows, while most feeding and migration take place far beyond the shoreline.

Size

40-51 cm long

Weight

650-1,000 g

Lifespan

Not reliably established

Status

Near Threatened

At sea, sooty shearwaters alternate quick wingbeats with low glides, banking to use wind above the waves. Feeding birds may gather in large flocks where prey concentrates. Around breeding colonies they usually come ashore after dark, reducing exposure to predators, and locate burrows using calls and scent cues. Partners share incubation and chick provisioning. Long-distance migration follows broad ocean circuits rather than a simple direct commute between nesting and nonbreeding areas. These shearwaters undertake one of the longest migrations of any animal, circumnavigating the Pacific Ocean annually in a figure-eight pattern. Pairs typically maintain the same burrow year after year, demonstrating strong site fidelity.

• Tracking studies have documented annual journeys exceeding 60,000 kilometers.
• The Māori name tītī is widely used for this species.
• Each breeding attempt normally involves a single egg.
• Adults can find their own burrows in crowded colonies at night.

October through April broadly overlaps New Zealand's breeding presence and offers opportunities to watch passing birds from suitable headlands. Passage intensity depends on wind, prey and locality. Colony attendance is mainly nocturnal, so the breeding calendar does not guarantee visible birds from shore. Prime viewing from a vessel's deck occurs during their migratory movements, particularly when they pass through nutrient-rich waters. Early morning or late afternoon can offer excellent light for spotting these birds at sea.

Breeding habitat consists of burrowable ground on coastal islands and some mainland sites, often beneath grass, scrub or forest. Outside the nesting burrow, the species is marine, ranging from productive continental-shelf waters to the open ocean. Coastal headlands can intercept passing flocks. Though widespread, the species faces habitat loss in some areas due to human development and introduced predators. Some New Zealand colonies are protected, allowing these birds to thrive in specific coastal sanctuaries.

Small fish, squid and crustaceans are the principal foods, taken at the surface or pursued below it using the wings. Diet changes with region and prey availability. Adults carry energy-rich food back to chicks after feeding trips that may cover substantial distances. They often dive to depths of 10 to 20 meters, though can reach 60-70 meters, using their powerful wings for propulsion. Feeding aggregations can be significant, sometimes involving thousands of birds converging on a food source.

Common name

Sooty shearwater

Scientific name

Ardenna grisea

Animal group

Birds

Size

40-51 cm long

Weight

650-1,000 g

Lifespan

Not reliably established

Status

Near Threatened

Identification

Compared with short-tailed shearwater, it generally shows a longer bill and more conspicuous silvery underwing panels, though distant birds can be difficult to separate. Note their uniformly dark plumage which can appear browner in some light, contrasting with the paler underwing that is a key ID feature. Pay attention to their flight style, as their stiff-winged glides are characteristic and help distinguish them from other similar-sized seabirds.