Chuck-will's-widow vs Common Murre

Antrostomus carolinensis compared with Uria aalge

Key Differences

Chuck-will's-widow is Least Concern while Common Murre is Critically Endangered.

Taxonomic Classification

Rank	Chuck-will's-widow	Common Murre
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Aves (Birds)	Aves (Birds)
Order	Caprimulgiformes (Caprimulgiformes)	Charadriiformes (Charadriiformes)
Family	Caprimulgidae	Alcidae
Genus	Antrostomus	Uria
Species	Antrostomus carolinensis	Uria aalge

Evolutionary Relationship

Chuck-will's-widow and Common Murre share a common ancestor at the Class level: Aves. (Birds)

View Class: Aves

Conservation Status

Chuck-will's-widow

LC — Least Concern

Common Murre

CR — Critically Endangered

Physical Characteristics

Attribute	Chuck-will's-widow	Common Murre
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chuck-will's-widow

Habitat

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

Range

Distributed across Colombia, Norway, and Venezuela.

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.

Chuck-will's-widow

The Chuck-will's-widow (Antrostomus carolinensis) is the largest nightjar in North America, named for its distinctive far-carrying call — a resonant four-syllable whistle repeated persistently on warm nights. It breeds across the southeastern United States, from the Atlantic coastal plain through the Gulf states and up the Mississippi Valley to southern Indiana and Kansas. The species migrates southward in autumn to winter quarters in the Caribbean, Central America, and northern South America. Like all nightjars, it is a crepuscular and nocturnal insectivore, capturing large moths, beetles, and other flying insects in flight using its enormous, bristle-fringed gape. By day, the Chuck-will's-widow roosts on the ground or along horizontal branches, relying on cryptic mottled plumage for concealment. It nests directly on the leaf litter of open woodland and scrub, typically in pine-oak forests, dry forests, and woodland edges. The IUCN classifies this species as Least Concern, though Breeding Bird Survey data suggest moderate long-term population declines linked to forest fragmentation and light pollution that disrupts insect prey availability. Conservation of large-scale woodland tracts in the southeastern United States benefits this species and its associated nightjar community.

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.