Also known as the sea pigeon, tystie and greenland dove, this medium-sized bird has two very different plumages.
Black guillemots are plump, medium-sized birds with pointed tails and rounded wings. Out of all of the birds in the auk family, black guillemots have the most extreme difference between their plumage. The summer plumage is brownish-black all over, with patches of white under the wing and on the top of the wings. In winter their plumage becomes mostly white with fringed black feathers, particularly on the back. During this time, they look mottled or finely barred in their appearance. The legs and feet and bright-red and bills are black and slender.
Both male and female look similar and juvenile birds are similar to the adult white plumage, but usually with more mottling on their neck and heads.
Black guillemot with winter plumage
Black guillemots are most vocal during the breeding season, especially during the early hours of the day. This becomes even more frequent when there are high numbers of birds present.
The alarm call is a lengthy, high-pitched call that is made with a stretched neck and opens bill that displays the red interior.
Black Guillemot call
Lars Edenius, XC546022. Accessible at www.xeno-canto.org/546022.
Black guillemot coming in to land on the sea
In the Scottish Isles, the black guillemot is known as the 'tystie'. This is said to be derived from the norse name for the bird.
Black guillemots diet varies seasonally and geographically, but it generally consists of fish and invertebrates - notably crustaceans, annelids and molluscs.
Black guillemots are resident in the UK and can be seen all year-round the coasts of Scotland and Northern Ireland. There are also small numbers of resident birds that can be found at St Bee's Head, along the coast of Cumbria and on the Isle of Man. They are mainly found along rocky cliffs and shores, usually close to areas with shallow water.
Black Guillemot with fish
The easiest time to identify black guillemots is when they have their summer plumage, which is a brownish-black colour with patches of white.
There is little information known about the pair formation of black guillemots. Breeding usually starts taking place between March or April, with birds arriving at their breeding sites as early as October. The nests are constructed out of a multitude of different materials including; small pebbles, dry vegetation, seaweed, feathers and bird and fish bones. Females will lay a clutch of usually two eggs, which is then incubated for around a month. The eggs vary in colour with anything from a dull white to a bluish-green and have dark spots distributed all over.
A black guillemot egg
The average lifespan of a black guillemot is around 11 years although there have been cases of birds living for up to 30 years!
ResidentThe United Kingdom Denmark Estonia Finland Iceland Ireland Norway Sweden Faroe Islands Greenland Saint Pierre and Miquelon
BreedingRussia Svalbard and Jan Mayen Islands Russia Canada United States of America Southern Russia