Found around the rocky coasts of Ireland and north-west Britain, this distinctive little seabird has a sharp black bill and scarlet feet.
In summer the Black Guillemot is all black, save for prominent white wing patches. In winter the plumage becomes almost white below with upperparts barred black-and-white. It is one of our smaller auks, only slightly larger than a Puffin and it has a thin whistling call.
The Black Guillemot is one of our most sedentary seabirds, only moving a short distance offshore in winter. The provision of nest boxes sited within harbour walls has helped this species.
Select a topic for more facts and statistics about the Black Guillemot
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 Black Guillemot, provided by xeno-canto contributors.
Other
Call
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Black Guillemots nest within rock crevices rather than in the open amongst other seabirds within cliff nesting colonies, and hence they are difficult to survey and counts were incomplete during the initial Seabird Census in 1969–70. The population remained broadly stable between the 1985–88 Census and Seabird 2000 (1998–2002) and annual data from the Seabird Monitoring Programme suggest it has been stable subsequently. Results from the recent Seabirds Count (2015–2021) are expected to offer a more comprehensive assessment of the recent trends (JNCC 2022).
Black Guillemots are highly sedentary and their principal range in both seasons is the coasts of Ireland, Anglesey, the Isle of Man and northern and western Scotland. In winter there are additional scattered records along the coasts of the North Sea and southwest and southern England, perhaps reflecting limited dispersal away from breeding areas.
Britain and Ireland Breeding Distribution 2008-2011. More from the Atlas Mapstore.
Britain and Ireland Winter Distribution 2008-2011. More from the Atlas Mapstore.
Breeding range change is most noticeable in the west of Scotland when compared with both of the previous atlases, with losses predominating in the Outer and Inner Hebrides, but striking gains are shown in the inner north Clyde area and on the east side of the Kintyre Peninsula.
Britain and Ireland Breeding Distribution Change 1968–72 to 2008–11. More from the Atlas Mapstore.
Britain and Ireland Winter Distribution Change 1981–84 to 2007–11 More from the Atlas Mapstore.
Change in occupied 10-km squares in the UK
% change in range in breeding season (1968–72 to 2008–11)
Black Guillemots are recorded throughout the year, though more consistently during summer at suitable coastal breeding sites.
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.
Movement
Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.
Foreign locations of birds ringed or recovered in Britain & Ireland
Encountered in:
Winter (Nov-Feb); Spring (Mar-Apr); Summer (May-Jul); Autumn (Aug-Oct)
Biology
Lifecycle and body size information about Black Guillemot, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.
Unlike other auks, Black Guillemots tend to remain close to their breeding colonies when foraging and the stable trend suggests that conditions have remained reasonably favourable over the last 30 or 40 years. However, knowledge of the breeding ecology is limited in comparison to many other seabird species and therefore further knowledge of this species would be valuable in order to understand possible threats.
Links to more information from ConservationEvidence.com
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