Common Murre vs Hourglass Dolphin

Uria aalge compared with Lagenorhynchus cruciger

Key Differences

• Common Murre is Critically Endangered while Hourglass Dolphin is Least Concern.

Taxonomic Classification

Rank	Common Murre	Hourglass Dolphin
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Aves (Birds)	Mammalia (Mammals)
Order	Charadriiformes (Charadriiformes)	Cetacea (Whales & Dolphins)
Family	Alcidae	Delphinidae (Oceanic Dolphins)
Genus	Uria	Lagenorhynchus
Species	Uria aalge	Lagenorhynchus cruciger

Evolutionary Relationship

Common Murre and Hourglass Dolphin share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Common Murre

CR — Critically Endangered

Hourglass Dolphin

LC — Least Concern

Physical Characteristics

Attribute	Common Murre	Hourglass Dolphin
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.

Hourglass Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

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.