Identification - Auks

Auks (Alcidae) - the penguins of the north-  are well known for their large breeding colonies on cliffs. Different species breed together and form massive colonies with over thousands of birds. The birds use the inaccessible cliffs only for breeding. When the breeding season is over, the birds move away from the cliffs and live the rest of the year at sea. Young birds jump from the cliffs even before they are able to fly. The Adult birds swim with their young to good foraging areas at open sea away from the coastlines.


There are no breeding colonies of auks in the Netherlands: our country lacks rocky shores with cliffs.  It is however possible to see members of this bird family within the Netherlands. There are 3 ways of getting these birds on your Dutch list: 1. birds in poor conditions or covered in oil, washing up ashore (not very nice), 2. distant views of birds fly by over sea, seen from the mainland with a telescope (difficult identification) or 3. join a bird pelagic and hope for birds showing up near the boat (not always easy!). The best period is the winter period from October to March. Razorbill (Alca torda) and Guillemot (Uria aalge) are the most common species, Little Auk, Puffin and Black Guillemot are rare, but have some records every year. Brünnich’s Guillemot is extremely rare, with only a few records ever.


Auks are compact, fast flying birds. When flying, they don’t make height and stay most of the time close to the water surface. From a distance Guillemot and Razorbill show extensive white, they look somewhat like white rugby balls with some dark top. The wings beat at a high frequency. At sea they often fly a couple of hundred meters to a few kilometres and then land again. From a single bird to small groups.


There are other species of salt-water birds that can look like a Razorbill of Guillemot. E.g. female Long-tailed Ducks can have a similar appearance but have broader wings and a less speedy flight. Grebes can also be mistaken for auklets but all grebes have longer legs extending far behind the bird and have far more white on their upper wings.

Common Guillemot (Uria aalge)

Most common of all the auklets on the North Sea, non-birders often think these are flying penguins. Best time between September and March.

On the water 

  • Short and square tail;
  • Long pointed bill;
  • Dark brownish upper parts;
  • Dark lines on the white flanks;
  • Head points upwards at a 45 degrees angle;
  • Darks band on the breast;
  • Dark eye-line, that extends on the cheeks.

In flight 

  • Short and square tail;
  • White secondary tips;
  • Thin dark breast band;
  • Dark markings on the white underwings;
  • White and dark parts on the thigh on the same level as the back towards the tail;
  • Feet extend the tail.

Razorbill (Alca torda)

Less common than Common Guillemot most of the time it’s about 1 Razorbill to 5 Common Guillemots. Best time between September and March.

On the water 

  • Long pointed tail;
  • Black upper parts;
  • Strong and stubby bill (largest with adult birds);
  • White flacks with no markings;
  • Not such a distinct eye-line;
  • More darker in the (fore)head;

In flight

  • Long pointed tail;
  • Black upper parts;
  • White of the thighs move up to the back of the rump, level with guillemots;
  • Clear white under wings;
  • Less pointed head.

Brunich’s Guillemot or Thick-billed Murre (Uria lomvia)

Vagrant to the Netherlands with nine records, only three living birds. Looks very similar to Common Guillemot or first winter Razorbill.

In flight

  • White underwing coverts
  • Short and square tail
  • Strong dark breast band
  • Overall dark head with white on the chin
  • White flanks
  • Black and white marking on the sides in a straight line like CG
  • Dark upper wings with white tips on the secondaries

On the water 

  • Short and square tail
  • White flanks, not striping like CG
  • More blackish upperparts like Razorbill, more dark-brown in CG
  • Shorter pointed, but broader, bill then CG
  • Far less white on the chin, looks very mottled with a dark breast band.
  • White of the breast moves up towards the throat into a point on the strong dark breast band, horizontal in CG
  • Has a more square head, flat in CG
  • No white on the ear coverts/cheek

Black Guillemot (Cepphus grylle)

Vagrant to the Netherlands but annual wintering (returning) birds.

On the water

  • Most remarkable of all auklets occurring along the Dutch coast;
  • White rump;
  • Short and square black tail
  • Black pointed bill
  • Red feet visible in clear water
  • Back can be all black to black/white marbled;
  • White patch on the black upper-wings, with dark lines in 1st winter plumage
  • Overall white plumage with dark spots on the head, neck, only full black area around the eye;

In flight

  • White rump;
  • Red feet;
  • Short and square black tail
  • White patch on the black upper-wings, with dark lines in 1st winter plumage
  • Overall white plumage with dark spots on the head, neck, only full black area around the eye;

Little Auk (Alle alle)

Scarce autumn and winter visitor. Best chance to see during or just after storms in November and December. Can also be found on fresh water after heavy storms.

On the water

  • Black upper- and white underparts
  • Small appearance and relative high on the water
  • Black breast band more diffuse to the front of the breast
  • Black head with white moving up from the breast over the ear coverts towards the neck
  • Short and stubby bill
  • Short tail

In flight

  • Black upper and underwings
  • Short and small stubby bird
  • Often in smaller flocks and closer to the shore
  • White secondary tips and white lines on the upper wing coverts
  • Short bill and round head
  • Short square tail;
  • Black upper-parts and white under-parts

Atlantic Puffin (Fratercula arctica)

Scarce winter visitor. Best time between September and March mainly along the Wadden Islands with northerly winds.

 In flight

  • Bulky and more dark appearance e.g. Razorbill / Guillemot
  • Larger bill can be visible by adults, immatures have smaller bill
  • Grey cheek
  • Dark grey underwings, black in LA and white in other auklets
  • All dark upper wings, not white line(s)
  • Orange legs can be visible in sunny conditions (while landing)
  • Dark band on the breast, encloses the grey cheek

On the water

  • Lies relative high on the water
  • Greyish cheeks
  • Dark band on the breast, encloses the grey cheek
  • Short and square tail
  • Black upper parts
  • White under parts
  • Round head which is kept more above the breast (slightly backwards)