Sooty Shearwater

Identification

The sooty shearwater is a medium-large seabird measuring 40–51 cm in length with a wingspan of 94–110 cm. Its most distinctive feature is its uniformly dark plumage, which appears nearly black in poor light but reveals itself as dark chocolate-brown in good conditions, with a characteristic silvery stripe running along the centre of the underwing. The species exhibits the typical "shearing" flight of its genus, dipping from side to side on stiff wings with minimal wing beats, the wingtips nearly touching the water—a powerful, direct style that gives the impression of a very small albatross.

In the Atlantic, the sooty shearwater is the only all-dark large shearwater, though it may be confused at long range with the smaller, usually paler Balearic shearwater, which lacks the pale underwing stripe. In Pacific waters, identification becomes more challenging; the short-tailed shearwater is almost impossible to distinguish at a distance. Vocal at night on breeding grounds with loud coos and croaks, sooty shearwaters are typically silent at sea, though they may call when competing for food in large groups.

Range & Habitat

Sooty shearwaters breed in two main populations: one in the south Pacific around southeast Australia, New Zealand, the Auckland Islands, and Phillip Island off Norfolk Island, and another in the south Atlantic on the Falkland Islands, Tierra del Fuego, and Tristan da Cunha. These spectacular long-distance migrants follow a remarkable circular route, traveling north up the western sides of the Pacific and Atlantic Oceans after the breeding season ends in March–May, reaching subarctic waters by June–July. They then cross from west to east before returning south down the eastern sides of the oceans in September–October, arriving at breeding colonies in November.

The distances covered are extraordinary; birds breeding in New Zealand may travel 74,000 km annually, reaching Japan, Alaska, and California, averaging more than 500 km per day. Atlantic populations from the Falkland Islands migrate north to 60–70°N in the North Atlantic off northern Norway, covering excess of 14,000 km. Flocks of hundreds of thousands have been observed migrating through locations like Monterey Bay, California. In Great Britain, they move south in late August and September, occasionally becoming trapped in the North Sea during strong northwesterly winds.

Behaviour & Diet

Sooty shearwaters are carnivorous, feeding on fish and squid. They are capable divers, reaching depths of up to 68 m, though they more commonly take surface food. They frequently follow whales to catch fish disturbed by them and also scavenge fish scraps thrown overboard from fishing boats. Isotopic analyses have revealed significant niche overlap between sooty shearwaters and great shearwaters, suggesting similar feeding strategies and prey preferences.

These birds breed in huge colonies, with females laying a single white egg averaging 48 mm in width and 77.5 mm in length. They nest in burrows lined with plant material, visiting only at night to avoid predation by large gulls and skuas. Breeding begins in October, with an incubation period of approximately 54 days, followed by a chick-rearing period of 86 to 109 days. In New Zealand, the species is known by its Māori name tītī and is traditionally harvested as muttonbird.

Best Time & Places to See It

The best viewing opportunities depend on location and season. In the Northern Hemisphere, sooty shearwaters pass through Atlantic and Pacific waters during their northward migration in June–July and southward migration in September–October. Monterey Bay in California is renowned for spectacular sightings, with flocks of hundreds of thousands visible during migration periods. In British waters, late August and September offer chances to see them, particularly along the east coast where they may retrace their route northward after becoming trapped in the North Sea during strong winds.

For those able to travel to breeding regions, the Southern Hemisphere offers the best opportunities. New Zealand, the Auckland Islands, and the Falkland Islands are major breeding centers. Visiting during the breeding season (October–January) provides the best chance of encountering large concentrations. However, dedicated pelagic trips and seawatch locations during migration periods offer the most accessible viewing for most travelers.

Photography Tips

Capturing sooty shearwaters presents both challenges and rewards. Their dark coloration requires careful exposure management; underexposure can render them as featureless silhouettes, while correct metering will reveal the subtle chocolate-brown tones and the crucial silver underwing stripe that aids identification. Photograph birds in flight when possible, as their characteristic shearing flight pattern is one of their most distinctive features and creates dynamic images.

During migration periods when birds congregate in large flocks, fast shutter speeds are essential to freeze rapid wing movements and erratic flight patterns. The best lighting conditions are side-lit or backlit scenarios that highlight the silvery underwing stripe and reveal plumage details. From boats or coastal vantage points, position yourself to capture birds in profile with wings extended to showcase their relatively long wingspan relative to body size. Early morning or late afternoon light often provides the most flattering illumination for these dark-plumaged seabirds.