Profile
In flight
Seabirds
Common Murre
Uria aalge
- rare
- 55 km/h
- Least Concern
Nests shoulder-to-shoulder on cliff ledges in colonies of millions. The world's most crowded mailbox.
- Population
- ~18 million mature individuals globally (BirdLife/IUCN 2018 assessment; overall global trend increasing), though with sharp regional divergence: Iceland's population has declined steeply since 2005 (European regional forecast of a 25-50% decline 2005-2050), and Alaska's population lost roughly half its birds following the 2014-2016 North Pacific marine heatwave ("the Blob"), with no recovery detected as of 2024
- Habitat
- Marine and coastal; breeds in dense colonies on sea cliffs, rocky offshore islands, and sea stacks, and forages in neritic waters over sandy-mud, rocky reef, seagrass, and kelp substrates, diving typically to depths of roughly 30-60 m with occasional dives recorded to about 180 m
- Fun fact
- Common Murres lay pear-shaped (pyriform) eggs on bare cliff ledges; one long-standing hypothesis is that the shape makes the egg roll in a tight circle rather than off the edge if bumped, though researchers have proposed several competing explanations (aerodynamic body shape, heat transfer, keeping the embryo's air cell clean of debris) and the rolling story alone is not fully settled.
- Range
- Circumpolar in low-Arctic and boreal waters of the North Atlantic and North Pacific, from eastern Canada and Greenland to Iceland, Scandinavia, the British Isles, Russia, and Japan, south to central California and the Iberian coast
- Diet
- Small schooling forage fish under about 20 cm (polar cod, capelin, sand lance, sprat, sandeel, Atlantic cod, herring), plus some squid and other invertebrates, caught by pursuit-diving
- Size
- 0.42 m
- Wingspan
- 0.67 m
- Lifespan
- 43 years
