Guillemot

Uria aalge

38-41cm

Appearance

This bird has relatively short wings, a proportionately long neck, and a straight, dark, sharp bill. The sexes are similar but plumage changes by season. In summer, birds are chocolatey brown on the head and upperparts, and birds of northern descent are darker than those from the south. The belly and breast are white but with dark flecks. Some northern birds have white markings around the eyes that are comparable to spectacles. Winter birds whiten around the throat and face, and there's a black line that runs back from the eye. Juveniles are similar to the winter adult, but they're smaller and have a shorter bill.

Habitat

Predominately lives on the open ocean, heading to land for the purpose of breeding. This takes place on the edges of cliffs, and sometimes on islands near shore.

Character

Colonies are big, and birds associate in fairly unstructured flocks when not breeding. Has a characteristic way of sitting up on cliff ledges rather than standing or laying down. Dives for food and uses its wings when under water.

Food

Eats fish, particularly cod, herring, whiting, sand eels and sprats, and may also eat crustaceans such as crabs.

Breeding

The sexes spend winter apart, then unite on breeding territory. Female lays one egg shaped like a pear on bare rock. Both adults incubate for 28-37 days, and when the chick hatches it has a layer of down. Within 3 weeks the chick departs the nest, though it cannot fly and is still growing, so the male accompanies it, feeding it on the open sea. Young can fly at about 8-10 weeks, and the male continues to feed it for about another 2 weeks.

Population

Males accompany juvenile birds over autumn and for majority of the first winter, when immatures form flocks separate from adults. Many birds spend winter in the North Sea, and some Scottish breeding birds head to the coast of Norway. Birds return to colonies during April. Approximately 950 000 pairs breed in the UK and 88 000 in Ireland.

Observation Tips

There should be little challenge in spotting a Guillemot in the region between May and July. They are often in sizeable colonies, and some of the best viewing spots are the Farne Islands, Pembrokeshire, and Noss in Shetland.

Voice

When on breeding grounds, has a nasally call, 'arrrr' that sounds similar to a growl.
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