Chuck-will's-widow vs Common Kidney-Vetch

Antrostomus carolinensis compared with Anthyllis vulneraria

Key Differences

Chuck-will's-widow is Least Concern while Common Kidney-Vetch is Vulnerable.

Taxonomic Classification

Rank	Chuck-will's-widow	Common Kidney-Vetch
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Magnoliophyta (Flowering Plants)
Class	Aves (Birds)	Magnoliopsida (Dicots)
Order	Caprimulgiformes (Caprimulgiformes)	Fabales (Legumes & Allies)
Family	Caprimulgidae	Fabaceae
Genus	Antrostomus	Anthyllis
Species	Antrostomus carolinensis	Anthyllis vulneraria

Conservation Status

Chuck-will's-widow

LC — Least Concern

Common Kidney-Vetch

VU — Vulnerable

Physical Characteristics

Attribute	Chuck-will's-widow	Common Kidney-Vetch
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 Kidney-Vetch

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and temperate coniferous forests, among 6 distinct biome types spanning the Indomalayan and Oceanian and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Libya), Asia (Japan), Europe (9 countries), North America (Canada, United States), and Oceania and the Pacific (Australia). Currently classified as Vulnerable 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 Kidney-Vetch

Common Kidney-Vetch (<em>Anthyllis vulneraria</em>) is a flowering plant in the legume family Fabaceae, assessed as Vulnerable on the IUCN Red List due to habitat degradation and agricultural intensification across parts of its range. It is widely distributed across Africa (Libya), Asia (Japan), Europe (nine countries), North America (Canada and the United States), and Oceania (Australia), occupying six distinct biome types and occurring within the Indomalayan and Oceanian biogeographic realms. The species typically grows in dry, calcareous grasslands, coastal cliffs, sand dunes, and rocky slopes, often favoring nutrient-poor soils. It is an important larval food plant for certain butterfly species, particularly the Small Blue butterfly in Europe, and contributes to soil fertility through nitrogen fixation via root nodules. Its cheerful yellow, orange, or red flower heads make it a recognizable component of chalk and limestone grassland communities. Biological traits of this species remain poorly documented in the scientific literature.