Guillemot

French: Guillaume, but ultimately onomatopoeic from the loud, high-pitched "will, willem" begging calls of the newly fledged young of the common guillemot.

They have distinctly white bellies, thicker and longer bills than Cepphus, and form very dense colonies on cliffs during the reproductive season.

Some prehistoric species are also known: Uria brodkorbi is the only known occurrence of the Alcini tribe in the temperate to subtropical Pacific, except for the very fringe of the range of U. aalge.

[8] Ornithologist Tim Birkhead experimented, and found that the arc that a pyriform egg rolls in is wider than most cliff ledges, so not protective against falls.

He attributed the egg's stability to its long straight edge resting on the ground, creating more friction and making it less likely to move and fall.

Common guillemots , one in bridled form (with "spectacles"), and one Brünnich's guillemot ( U. lomvia , with white-marked bills) from the genus Uria
Black guillemot ( C. grylle ) from the genus Cepphus
Common guillemot in bridled form, a white circle around the eye with an extension backwards suggesting they are wearing spectacles