Cory's Shearwater

Calonectris diomedea

45cm

Appearance

A large and arresting seabird, Cory's Shearwater has a sturdy build, and a large head and wingspan. The sexes are similar; upperparts are a medium-brown, though the wings have a darker tip, as does the tail. Its underparts are white and its pale bill is yellowish with a dark tip, though this can only be seen at close range. The underwing is very white with a neat dark rim around the edge and tip. The juvenile bird appears similar to the adult.

Habitat

This is a scant visitor in the summer, arriving from the rocks and scree of its breeding islands in the Mediterranean. It lives on the open sea and moves large distances out of the sight of land.

Character

When flying it can appear casual as it makes slow downward wingbeats and then glides long and low on bowed or stiff wings; when conditions are calm, it flaps its wings in a way comparable to a gull, while when it's windy, it may bank and tower. Regularly follows the movement of ships and associates with whales and dolphins, and may be seen in small flocks. It feeds from the water's surface, but also dives beneath it.

Food

Herring and other sea creatures such as squid and crab are part of this bird's diet, as is waste discharged from fishing vessels.

Breeding

Does not breed in Britain or Ireland. Nesting takes place in colonies, usually among rocks or in tunnels and caves. The female lays only one egg; both parents tend to the chick, though it is deserted and left to make its own way to the ocean.

Population

It's at breeding grounds from February to October; some birds make their way north after breeding and reach the Bay of Biscay and the south-west coast of Britain and Ireland. Between April and early October, smaller numbers are seen off the east coast of England; there are up to 1500 sightings each year around Britain and Ireland, but annual numbers vary.

Observation Tips

Trips on the open ocean provide a chance of sighting this bird, such as ferry crossings between Cornwall and the Scilly Isles in late August and September. Also may be seen on occasion off headlands in west Wales and southern Ireland.

Voice

Predominately silent in the region.
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