Cory’s Shearwater

Identification

Cory's shearwater is a large seabird measuring 45–56 cm in length with a wingspan of 112–126 cm. Its most distinctive features are brownish-grey upperparts contrasting with white underparts, and a characteristic yellowish bill. Unlike the similarly sized great shearwater, Cory's lacks a brown belly patch, dark shoulder markings, and black cap, making it relatively straightforward to identify in the field.

Range & Habitat

This species breeds colonially on several Atlantic islands, including Madeira, the Azores, the Berlengas Archipelago in Portugal, and the Canary Islands in Spain. Outside the breeding season, Cory's shearwater ranges widely throughout the Atlantic. In late summer and autumn, most birds migrate northward as far as the southwestern coasts of Great Britain and Ireland, before returning to the Mediterranean in February. The largest colony is located in the Savage Islands, Madeira.

Behaviour & Diet

Cory's shearwater is highly gregarious and can often be seen in large numbers. Its flight is distinctive, characterized by long glides with wings held bowed and angled slightly back—quite different from the stiff, straight-winged flight of the great shearwater. The species feeds on fish, molluscs, and offal, and is capable of diving to depths of 15 metres or more in pursuit of prey. It readily follows fishing boats, where groups engage in noisy squabbles over food scraps. At sea, Cory's shearwater is silent, but breeding colonies come alive at night with loud, raucous cackling calls.

Best Time & Places to See It

Late summer and autumn offer the best opportunities to observe Cory's shearwater in northern Atlantic waters. The Bay of Biscay ferries are particularly renowned for excellent sightings, as this gregarious species congregates in large numbers in accessible areas. Appropriate coastal headlands can also yield good views. For breeding birds, the Azores and other island colonies attract specialized wildlife tours, though visits are typically restricted to minimize disturbance.

Photography Tips

From ferry crossings, photograph this species in its natural element as it glides low over the water with characteristic bowed wings. The contrast between brownish-grey upperparts and white underparts provides good definition for photography. Early morning or late afternoon light will enhance the subtle plumage tones. When following fishing boats, be prepared for dynamic action shots as birds engage in competitive feeding behaviour. At breeding colonies (where accessible), night photography with appropriate red-light filters can capture the dramatic cackling interactions, though a tripod and slow film speed will be essential.