Scopoli's Shearwater: where and when to see them

Scopoli's shearwater is a large Mediterranean seabird that spends most of its life at sea, coming ashore primarily to breed on islands and rocky coastal sites. Formerly grouped with Cory's shearwater, it is now generally recognized as a separate species. Its long, flexible-looking wings suit economical travel over open water. After breeding, many birds leave the Mediterranean and range widely through the Atlantic before returning the following spring.

Size

45–52 cm body length; 112–122 cm wingspan

Weight

600–1,000 g

Lifespan

Not reliably established

Status

Least Concern

At sea, these shearwaters alternate shallow wingbeats with long glides, often following the contours of waves. They gather where food is concentrated but disperse widely between feeding opportunities. Breeding birds usually approach colonies after dark, reducing exposure to predators. Pairs occupy burrows, rock crevices or sheltered cavities, share incubation of a single egg, and make repeated feeding journeys while their chick remains at the colony. Courtship rituals involve nocturnal aerial displays and calls around the colony sites before pairs settle into their chosen nest cavities. Adults are highly vocal at night when at the colony, producing eerie wailing and cackling calls that are characteristic of the species.

• A breeding pair normally lays just one egg in a season.
• Many individuals cross the Strait of Gibraltar during migration.
• Its tubular nostrils are characteristic of the seabird order Procellariiformes.
• Adults produce striking, harsh calls at colonies despite often being quiet at sea.

April through October is the most useful broad Mediterranean viewing period, overlapping colony attendance and movements through nearby waters. Coastal passage varies by locality and weather. Winter observations are less dependable because much of the population disperses into the Atlantic. Peak breeding activity and chick rearing extend from June to September, making these months particularly productive for observing parent birds at sea. During spring and autumn migration, large rafts of shearwaters can be seen resting on the water's surface in sheltered bays and channels.

The species feeds over Mediterranean coastal and offshore waters, with breeding colonies on islands, sea cliffs and rocky slopes offering protected cavities. Outside the breeding period it uses Atlantic marine habitats, sometimes far beyond any practical shore-based viewing distance. The species is a summer resident across the Mediterranean, preferring arid and semi-arid islands, often those with steep cliffs and limited human disturbance. Important breeding sites exist throughout the Aegean and Ionian Seas, including several islands within the proposed cruise destinations.

Small schooling fish, squid and crustaceans make up much of its diet. Birds take prey at or just below the surface and sometimes exploit fishery discards. Feeding distribution shifts with currents, prey movements and temporary concentrations of marine life. They are opportunistic feeders, often joining mixed flocks with other seabirds and cetaceans to exploit transient food sources. Their diet may also include offal and discarded fish from fishing vessels, which can impact their foraging behavior.

Common name

Scopoli's Shearwater

Scientific name

Calonectris diomedea

Animal group

Birds

Size

45–52 cm body length; 112–122 cm wingspan

Weight

600–1,000 g

Lifespan

Not reliably established

Status

Least Concern

Identification

Compared with Cory's shearwater, Scopoli's usually shows more white extending into the underside of the outer primaries, although distant birds may be inseparable. Key distinguishing features from Cory's shearwater include a slightly smaller bill that is typically yellower, and the underwing pattern which shows more contrast between the white wing lining and the darker flight feathers. The primary patch of Scopoli's also appears to extend further onto the inner wing when seen from below.