Granddad’s Camera
Guillemot, as it appears in the game

No.056 · Birds · Common

Guillemot

Uria aalge

A dark brown-and-white auk that packs shoulder to shoulder on open cliff ledges, laying a single pointed egg with no nest.

When to look

April to July, mostly at dawn and day.

Time of day

Best time
Skomer cliffs, roughly April to late July; jumplings in late June and early July.
Where in the game
the Pembrokeshire coast (island, sea cliff and sea)
Size
Body 38–46 cm
Wingspan
61–73 cm
Weight
About 890 g (770–1,010 g)
Lifespan
Typically 23 years once breeding; a ringed bird reached nearly 41 years (BTO)
Population
950,000 pairs in the UK (BTO, 1998–2002); the Seabirds Count census found 8% fewer birds than Seabird 2000. 29,358 birds counted on Skomer in 2024 (Wildlife Trust of South & West Wales)
Status
Amber list, UK Birds of Conservation Concern (BTO)

Diet

Fish such as sand eels and sprats, caught by diving deep from the surface

Habitat

Cliff ledges in dense colonies; otherwise far out at sea

Breeding

One egg per year, laid on bare rock (first egg on Skomer 27 April in 2024). The chick leaves at 18–25 days, gliding to the sea with its father (first jumpling on Skomer 22 June in 2024)

Field signs

  • Dense rows of upright birds on cliff ledges, brown-black above and white below
  • A thin, pointed bill (a razorbill's is thick and blunt)
  • Some birds show a white eye-ring and line: the 'bridled' form
  • A deep, growling 'arrrr' from the ledges

Did you know?

  • A guillemot's egg is pear-shaped, which is thought to help it roll in a tight circle rather than off the ledge.
  • Chicks jump at around three weeks old, before they can fly, and their dads guide them out to sea.
  • Guillemots spend nearly all their lives at sea, where they are vulnerable to oil spills (RSPB).

Moments worth waiting for

  • Ledge jumpers June to July, dusk and dawn
    A chick shuffles to the edge and tumbles out, whirring tiny wings as it plops into the sea beside its father.

Rare forms and local legends

  • Bridled guillemot A rare colour form, about 1 in 200 sightings
    The bridled form has a white eye-ring and a white line back from the eye. Around 1 in 200 guillemots on Skomer were bridled in 1946; in Shetland it's about a quarter, and over 70% in Iceland.
  • Bridle Bess A local legend
    Guillemots return to the very same ledge year after year. Skomer's guillemots have been studied every year for over four decades.

Photo tip

From a boat below the cliffs you can shoot a whole wall of birds: 200–400 mm with a fast shutter. From above, watch for the bridled ones. Keep the horizon level and avoid harsh midday glare on white fronts by shooting in the softer light of morning.

Be a good naturalist

Stay on the path and away from cliff edges; ledge colonies are easily flushed and their eggs are quickly taken by gulls. On the water, follow the Pembrokeshire Marine Code: slow down, keep a steady course and back off at any sign of birds craning or flapping.

The law

Protected as a wild bird under the Wildlife and Countryside Act 1981; part of the Skomer, Skokholm and the seas off Pembrokeshire protected areas

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