Devon Wildlife Trust: These chocolate-brown birds nest in noisy, tightly packed colonies on steep ledges around the coast. They have a very small territory, so small that it only extends a beak’s-length around its nest! Female guillemots lay a single egg a year and once its chick is three weeks old, it will dive off the cliff into the sea with its father. The father will look after the chick in the sea until it is old enough to look after itself. Guillemots eat fish, crabs and molluscs, diving down into the sea and using their wings to swim after their prey.
How to Identify:
The guillemot is chocolate-brown above and white below. A 'bridled' form occurs, where the eye is ringed with white, which extends as a line towards the neck. In winter, guillemots have white faces. The similar-looking razorbill is blacker in colour, and has a thicker and shorter bill.
https://www.devonwildlifetrust.org/wildlife-explorer/birds/seabirds/guillemot
RSPB - Guillemot Bird Facts
The UK's coasts have many stretches of sheer cliffs where seabirds breed and the guillemot is one of the most numerous birds in the great 'seabird cities'. It comes to land only to nest, spending the rest of its life at sea, where it is vulnerable to oil spills. Dark brown and white, not as black as the similar razorbill, it has a 'bridled' form with a white ring round the eye and stripe behind it.
Guillemot are found on small areas of cliffs on the south coast of England, very locally on the coasts and islands of Wales and in a handful of places in the north of England and Northern Ireland. More widely spread on cliffs of Scotland. RSPB nature reserves such as Bempton Cliffs in Yorkshire, Fowlsheugh in Grampian and Marwick Head in Orkney have large colonies. In winter it is widespread around UK coasts but usually well offshore. It is sometimes seen inshore after gales or passing by longer headlands.
https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/guillemot/
Guillemots in non-breeding plumage, Morte race, 29th August 2020. Photo taken from MS Oldenburg by Grant Sherman
Devon Birds: Search the Devon Birds website for recent sightings of Guillemots in Devon.
Wikipedia The common murre or common guillemot (Uria aalge) is a large auk. It is also known as the thin-billed murre in North America. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.
Common murres have fast direct flight but are not very agile. They are more manoeuvrable underwater, typically diving to depths of 30–60 m (98–197 ft). Depths of up to 180 m (590 ft) have been recorded.
Common murres breed in colonies at high densities. Nesting pairs may be in bodily contact with their neighbours. They make no nest; their single egg is incubated on a bare rock ledge on a cliff face. Eggs hatch after ~30 days incubation. The chick is born downy and can regulate its body temperature after 10 days. Some 20 days after hatching the chick leaves its nesting ledge and heads for the sea, unable to fly, but gliding for some distance with fluttering wings, accompanied by its male parent. Chicks are capable of diving as soon as they hit the water. The female stays at the nest site for some 14 days after the chick has left.
Both male and female common murres moult after breeding and become flightless for 1–2 months. In some populations they occasionally return to the nest site throughout the winter. Adult birds reduce the time that they spend flying during the winter and are able to forage nocturnally
https://en.wikipedia.org/wiki/Common_murre
eBird Black-and-white seabird with crisp patterning. Dark brownish-black above with white belly. Head entirely dark in breeding plumage; nonbreeding show white face with curved dark line below eye. Sides usually show some messy dark streaks. Bill is longer and more slender than similar Thick-billed Murre; but can be difficult to judge at a distance. Also note browner plumage and streaky sides on Common Murre. Breeds in colonies on rocky islands and cliffs; spends the rest of the year on the ocean. Usually single or in loose small groups; in the Atlantic, sometimes seen in loose association with Razorbills.