Details
Uria aalge
The common murre is an auk that forms dense colonies on northern sea cliffs. Underwater it swims with its wings to chase fish.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It inhabits cold Arctic, North Atlantic, North Pacific, Palearctic, and Nearctic seas. Breeding takes place on narrow ledges of coastal cliffs.
Length is 38-46 cm and weight 850-1300 g. It has a dark brown-black head and back, white underparts, a pointed bill, and an upright stance on ledges.
Diurnal and highly colonial, it crowds tightly at breeding cliffs. At sea it dives and uses its wings like flippers to pursue prey.
A carnivore, it feeds mainly on small fish such as sand lance and herring relatives. It chases prey underwater and carries fish crosswise in the bill to chicks.
No nest is built; a single egg is laid directly on the rock ledge. The pear-shaped egg resists rolling, and the chick leaves the cliff for the sea before it can fly well.
It is listed as Least Concern. Oil pollution, fishing-net bycatch, and changes in forage fish can pose local risks.
