Chuck-will's-widow vs Common Silver Hairgrass

Antrostomus carolinensis compared with Aira caryophyllea

Key Differences

Chuck-will's-widow is Least Concern while Common Silver Hairgrass is Endangered.

Taxonomic Classification

Rank	Chuck-will's-widow	Common Silver Hairgrass
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Magnoliophyta (Flowering Plants)
Class	Aves (Birds)	Liliopsida (Monocots)
Order	Caprimulgiformes (Caprimulgiformes)	Poales (Grasses)
Family	Caprimulgidae	Poaceae (Grass Family)
Genus	Antrostomus	Aira
Species	Antrostomus carolinensis	Aira caryophyllea

Conservation Status

Chuck-will's-widow

LC — Least Concern

Common Silver Hairgrass

EN — Endangered

Physical Characteristics

Attribute	Chuck-will's-widow	Common Silver Hairgrass
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 Silver Hairgrass

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical grasslands and savannas, and flooded grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Cameroon), Asia (Japan, South Korea), Europe (6 countries), North America (4 countries), Oceania and the Pacific (Australia), and South America (4 countries). Currently classified as 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 Silver Hairgrass

<em>Aira caryophyllea</em>, commonly known as Common Silver Hairgrass, is a slender annual grass belonging to the family Poaceae within the order Poales. This delicate grass is currently classified as Endangered on the IUCN Red List, reflecting significant conservation concern despite its historically broad distribution. It is typically found across a remarkable diversity of biome types, including tropical and subtropical moist broadleaf forests, grasslands, savannas, and flooded habitats, demonstrating notable ecological versatility. Its geographic range spans multiple continents, with documented populations in Africa (Cameroon), Asia (Japan, South Korea), Europe, North America, Australia, and South America. As an annual grass, it completes its life cycle within a single growing season, reproducing via wind-dispersed seeds. The inflorescence typically bears silvery, shimmering spikelets that give the species its common name. Biological traits such as average lifespan, body dimensions, and dietary specifics follow typical patterns for annual grasses — drawing nutrients from soil through root absorption rather than consuming other organisms. The endangered status suggests populations may be declining due to habitat loss, land-use change, or invasive species pressure across parts of its range.