Common Murre vs Thick-billed Murre

Uria aalge compared with Uria lomvia

Key Differences

• Common Murre is Critically Endangered while Thick-billed Murre is Endangered.

Taxonomic Classification

Rank	Common Murre	Thick-billed Murre
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Aves (Birds)	Aves (Birds)
Order same	Charadriiformes (Charadriiformes)	Charadriiformes (Charadriiformes)
Family same	Alcidae	Alcidae
Genus same	Uria	Uria
Species	Uria aalge	Uria lomvia

Evolutionary Relationship

Common Murre and Thick-billed Murre share a common ancestor at the Genus level: Uria.

Conservation Status

Common Murre

CR — Critically Endangered

Thick-billed Murre

EN — Endangered

Physical Characteristics

Attribute	Common Murre	Thick-billed Murre
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Murre

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Distributed across Belgium, Denmark, Norway, Sweden, and United States. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Thick-billed Murre

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Distributed across Belgium, Denmark, Norway, Sweden, and United States. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Murre

<em>Uria aalge</em>, the common murre or common guillemot, is a seabird in the family Alcidae found across the North Atlantic and North Pacific Oceans. This colonial cliff-nesting bird typically breeds on rocky coastal ledges and sea stacks, often in dense aggregations that may number in the thousands. <em>Uria aalge</em> is a highly capable diver, using its wings to propel itself underwater in pursuit of fish, sand eels, and invertebrates. It is found in coastal and offshore marine waters during the non-breeding season, ranging across the northern seas. Recorded occurrence countries include Belgium, Denmark, Norway, Sweden, and the United States. Despite its wide distribution and historically large numbers, the common murre is currently assessed as Critically Endangered in certain regional contexts, with populations threatened by oil spills, bycatch in fishing nets, food web disruptions linked to climate change, and disturbance at breeding colonies. Biological traits such as lifespan, body size, and diet remain poorly documented at the population level for this species across its full range, though it is known to be a piscivore. The species is a key indicator of marine ecosystem health and a focus of ongoing seabird conservation efforts.

Shared Countries

Both species can be found in 5 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States