Common murre/guillemot (Uria aalge)

Colonies at the bottom of the cliffs in Sunburgh Head (Shetland I., 2013)
Guillemots are 38-45 cm in size. They nest in colonies on cliff edges. Their eggs are pear-shaped so they don´t roll off. The bridled form has a white ring round the eye, which looks like a pair of spectacles (you can see some of them like this if you look closely). The spectacles like form is not a distinct subspecies, but a polymorphism that becomes more common the farther north the birds breed.