Cormorant

Phalacrocorax carbo

80-100cm

Appearance

This bird is the size of a big goose and has a green eye, a large bill with a hooked tip, a broad neck and a graded forehead. The sexes are similar but there is some difference in plumage across the seasons. The summer adult is dark, with black-bordered brownish wing feathers in good light. It has yellow at the bill's base which fades to white. In spring it has patches of white on the thigh, head and neck; the winter birds lose these white feathers. Juvenile birds have brown upperparts and pale underparts, and they accumulate adult plumage over two years.

Habitat

Breeding sites are formed during spring and summer around rocky cliffs and islands in Ireland and the south, west and north of Britain. Increasingly found near lakes and rivers too, where they're more likely to build nests in trees.

Character

This bird may often be seen alone, although at sites of nesting and feeding it will be in larger groups; its nesting colonies can have more than 100 nests. When flying, its neck is extended and groups may fly in lines or V formation; it finds perches on the ground, on posts, power-lines, pylons or in trees, and it often stands with its wings stretched out to dry. It leaps before diving for fish and uses its big feet to move powerfully through the water.

Food

Diet includes fish, particularly flatfish like plaice and flounder, and it also catches cod, sprats and blennies, and trout when the birds are living on inland waters.

Breeding

Parents share the job of incubating 3 or 4 eggs for approximately 30 days. When they're little, the young are brooded and they return to the nest to be fed for about 40-50 days, after which they become independent. First breeding can occur after 3 years.

Population

These are resident birds in the region, though they disperse from breeding colonies once the young can fly; some birds make it to France, Spain or Portugal. The population is boosted by winter arrivals from northern Europe to the south-east England. There are more than an estimated 8 000 pairs in the UK and 4 550 in Ireland, and the winter influx raises populations to above 54 000 individuals in Britain and in Ireland.

Observation Tips

An uncomplicated bird to spot and to distinguish, although it is sometimes confused with the Shag.

Voice

It's vocal at breeding colonies; deep, nasal sounds such as 'agock-agock-agock' are made by adults. Predominately quiet at other times.
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