• Name: Guillemot/Common Murre | Uria aalge
  • Size: 64-73cm wingspan
  • Life span: 23 years
  • Diet: Guillemot eat fish, crabs and molluscs, diving down into the sea and using their wings to swim after their prey.
  • Reproduction: 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.
  • When to see: Spring and Summer  (Mid March to end of July)
  • Where to see: Out at sea or on rocky outcrops during breeding season i.e. Western Rocks | St Martin's Head, St Martins | Menawethan | Norrard Rocks in Scilly.
  • Conservation status: ICUN Redlist | Least Concern.
  • Population Trend: Increasing
  • Threats:  Human activity (i.e. disturbance), pollution, climate change (changes in weather patterns, changing sea temperatures). 
  • Fun Fact: Guillemot have a very small territory, so small that it only extends a beak’s-length around its nest!

Description: The Guillemot belongs to the Auk family, 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, Guillemot have white faces.

They can easily be confused with the similar-looking Razorbill (also an Auk) which is blacker in colour, and has a thicker and shorter bill.

Guillemot typically lay one egg, directly onto rock. The male and female birds take turns to incubate the egg, balancing it on their feet, covering it with their belly plumage.  Eggs are very narrow and pointed at one end (pyriform, or pear-shaped). The purpose of this shape is still debated, but one leading theory is that this shape makes them more stable, reducing the risk of them rolling off rocks where they are laid!

The Guillemot egg is widely considered as one of the most beautiful and extraordinary eggs in the avian world.

After about 4 weeks, a grey, almost helpless youngster hatches and it will stay on its ledge for four to five weeks.

The parents continually fly in and out from the colony to catch fish and regurgitate meals for their baby.  Guillemot are "single prey loaders"; meaning they will only carry one fish at a time, unlike other members of the Auk family. 

The Guillemot is the second most prolific of the three Auks (the family that Guillemot, Razorbill and Puffins belong to) found here in Scilly, and is larger than the Puffin but smaller than the Razorbill.

Want to know more?  Check out our latest Seabird Monitoring & Research Technical Report for the most up to date information about how this species is fairing in Scilly.


Do remember that we rely on donations to continue our work.  If you have searched, found and learned about Scilly's wildlife on our website, please Support Us and give what you can.  Thank you 💚

Support Us


With thanks to Joe Pender for the Guillemot image