Common Murre
Uria aalge
崖海鸦
Introduction
A large auk (family Alcidae, genus Uria) with circumpolar distribution in low-Arctic and boreal waters of the North Atlantic and North Pacific. Marine species spending most time at sea, only coming to land to breed on rocky cliff shores or islands. Highly mobile underwater, using wings to 'fly' through the water column; typically dives to depths of 30-60m, with records up to 180m. Population estimated at 18 million individuals, though a massive die-off in the northeast Pacific between 2014-2016 killed approximately half of Alaska's population, representing the largest documented wildlife mortality event in the modern era.
Description
Length 38-46 cm with wingspan 61-73 cm. Weight ranges from 945g in southern populations to 1,044g in northern populations (775-1,250g reported). Breeding plumage shows black head, back and wings with white underparts, thin dark pointed bill, and small rounded black tail. Post-breeding moult results in white face with dark spur behind eye and dark streaks on flanks. Subspecies U. a. albionis appears dark brown rather than black. Legs dark grey, occasionally yellow-grey. 'Bridled' morph has white eye ring extending back as white line. Chicks downy with blackish upperparts and white underparts.
Identification
In field, sexes appear identical. Distinguished from similar thick-billed murre (U. lomvia) by thinner, more pointed bill lacking thick base. 'Bridled' morph with white eye ring distinguishes some individuals, more common in northern populations (not a subspecies but polymorphism). Dark brown plumage of U. a. albionis subspecies distinguishes southern British Isles populations. Adult winter plumage shows white face with dark spur behind eye, unlike breeding plumage.
Distribution & Habitat
Breeds on islands, rocky shores, cliffs and sea stacks across North Atlantic and North Pacific. Five subspecies recognized: U. a. aalge (southeast Canada, Greenland, Iceland, Scotland, Scandinavia, Baltic), U. a. hyperborea (northern Norway to Svalbard and Novaya Zemlya), U. a. albionis (British Isles to Iberian Peninsula), U. a. inornata (Russia, Japan, Aleutians to Alaska), U. a. californica (Washington to California). Northern populations migrate south to New England, southern California, Japan, Korea, and Mediterranean; UK populations largely resident but may reach Barents Sea.
Behavior & Ecology
Pursuit-diver foraging underwater using wings for propulsion. Diet primarily small schooling fish 200mm or less (capelin, sand lances, herring, cod, sprats), plus molluscs, worms, squid, and crustaceans. Consumes 20-32g daily. Monogamous, breeds at ages 4-9 years in densely packed colonies on bare rock ledges. No nest; egg incubated between adult's feet for 28-34 days. Chick leaves ledge at 20 days, accompanied by male parent at sea for up to two months. Vocalizations include growling 'murrrr' call and chick's high-pitched 'willee' whistle. Both sexes moult post-breeding, becoming flightless 45-60 days.
Conservation
Population estimated at 18 million individuals. IUCN assessment not specified in source. Massive die-off: 52-78% decline at 13 Alaska colonies between 2016-2022, losing 4 million birds following marine heatwave (2014-2016). No evidence of recovery as of 2024. Threats include hunting (legal in Newfoundland), pollution, oil spills (doubling winter mortality of breeders), and climate change. Major oil spills have limited effect on birds under 3 years; increased recruitment of 4-6 year olds can compensate for breeding adult losses.
Culture
Hunted for food in Newfoundland and Labrador, where birds along with thick-billed murres are locally called 'turrs' or 'tuirs'. Dark, oily meat from fish diet. Eggs historically harvested; San Francisco eggers took nearly 500,000 eggs annually from Farallon Islands in mid-19th century. Birdwatchers petitioned for UK Sea Birds Preservation Act 1869 to reduce shooting and egg collecting during breeding. Current concerns include managing visitor impact at wildlife reserves and seasonal climbing bans on nesting cliffs.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Charadriiformes
- Family
- Alcidae
- Genus
- Uria
- eBird Code
- commur
Vocalizations
Subspecies (5)
-
Uria aalge aalge
breeds North Atlantic coasts and islands of coastal southwesstern Greenland, Iceland, Faroe Islands, Scotland, southern Norway, and Baltic Sea, also southeastern Canada; winters offshore to south
-
Uria aalge albionis
breeds British Isles southward to western Iberian Peninsula and eastward to Helgoland
-
Uria aalge californica
coastal northern Washington to southern California
-
Uria aalge hyperborea
breeds Svalbard through northern Norway and northwestern Russia eastward to Novaya Zemlya
-
Uria aalge inornata
breeds coastal Kamchatka, Sakhalin, Kuril and Commander islands (eastern Russia), southern Kuril Islands, Teuri Island (northwest of Hokkaido; formerly also Hokkaido; northern Japan), also Aleutian and Bering Sea islands to western Alaska and southwestern Canada
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Bird images and sounds sourced from GBIF, contributed by citizen scientists worldwide under Creative Commons licenses.
Taxonomy data from AviList 2025.