Common Guillemot (Uria aalge) is a large auk. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.
These birds have a fast direct flight but are not very agile. They are more manoeuvrable underwater, typically diving to depths of 30–60 m.
They make no nest; their single egg is incubated on a bare rock ledge on a cliff face for 30 days.
Around 20 days after hatching the chick heads for the sea, unable to fly, but gliding for some distance with fluttering wings, accompanied by its father.
Chicks are capable of diving as soon as they hit the water.