Uria aalge (Pontoppidan, 1763) GU GUILL 6340
Family: Charadriiformes > Alcidae

Guillemot, Mike Toms

Guillemots breed on rocky cliffs, using narrow ledges, and their colonies can be found around much of our coastline, including on isolated seastacks and suitable island outcrops.

Colonial breeding is the norm in this species and some colonies may number tens of thousands of individuals. Nest site locations vary between sites, with mainland sites restricted to narrow ledges safe from predators; on predator-free islands pairs may nest among rocks or even on bare ground.

During the winter months Guillemots may be encountered widely in coastal waters, though these birds are most abundant in those of the northern North Sea and off our western shores.


Guillemot identification is usually straightforward. The following article may help when identifying Guillemot.

related video

Identifying winter Auks

Summer Auks, in breeding plumage, at the shore or near to their colonies are relatively easy to identify. But in autumn and winter we tend to see them flying rapidly past, far offshore, or bobbing around in heavy seas offering poor views. When you add to this that their distinctive breeding plumage and colouring is lost, winter Auks can be a serious challenge to identify and separate.


Listen to example recordings of the main vocalisations of Guillemot, provided by xeno-canto contributors.



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Status and Trends

Population size and trends and patterns of distribution based on BTO surveys and atlases with data collected by BTO volunteers.


This species can be found on the following statutory and conservation listings and schedules.



During winter, Guillemots are found around much of the coast of Britain & Ireland with the highest densities in west-coast waters and the North Sea coast of southeast Scotland and northeast England. Guillemot colonies are associated with steep cliffs and rocky offshore stacks and islands, and the lack of these habitats between Flamborough Head, Yorkshire and Durlston Head, Dorset is mirrored in the breeding distribution map.

Occupied 10-km squares in UK

European Distribution Map

European Breeding Bird Atlas 2


Change in occupied 10-km squares in the UK


Guillemots are recorded throughout the year though more consistently during summer at suitable coastal breeding sites.

Weekly occurence of Guillemot from BirdTrack
Weekly occurrence patterns (shaded cells) and reporting rates (vertical bars) based on BirdTrack data. Reporting rates give the likelihood of encountering the species each week.


Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.


View a summary of recoveries in the Online Ringing Report.

Foreign locations of birds ringed or recovered in Britain & Ireland

Foreign locations of Guillemot ringed or recovered in Britain & Ireland
Encountered in: Winter (Nov-Feb); Spring (Mar-Apr); Summer (May-Jul); Autumn (Aug-Oct)


Lifecycle and body size information about Guillemot, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.



View number ringed each year in the Online Ringing Report


Feather measurements and photos on featherbase


For information in another language (where available) click on a linked name

Gaelic: Eun-dubh-an-sgadain
Welsh: Gwylog
Catalan: somorgollaire comú
Czech: alkoun úzkozobý
Danish: Lomvie
Dutch: Zeekoet
Estonian: lõunatirk
Finnish: etelänkiisla
French: Guillemot marmette
German: Trottellumme
Hungarian: lumma
Icelandic: Langvía
Irish: Foracha
Italian: Uria
Latvian: tievknabja kaira
Lithuanian: laibasnapis narunelis
Norwegian: Lomvi
Polish: nurzyk (zwyczajny)
Portuguese: airo
Slovak: norec tenkozobý
Slovenian: lumna
Spanish: Arao común
Swedish: sillgrissla
Folkname: Loom, Willock

Links to more information from

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