Chuck-will's-widow vs Great Hammerhead

Antrostomus carolinensis compared with Sphyrna mokarran

Key Differences

• Chuck-will's-widow is Least Concern while Great Hammerhead is Critically Endangered.

Taxonomic Classification

Rank	Chuck-will's-widow	Great Hammerhead
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Aves (Birds)	Chondrichthyes (Cartilaginous Fish)
Order	Caprimulgiformes (Caprimulgiformes)	Carcharhiniformes (Ground Sharks)
Family	Caprimulgidae	Sphyrnidae (Hammerhead Sharks)
Genus	Antrostomus	Sphyrna (Hammerhead Sharks)
Species	Antrostomus carolinensis	Sphyrna mokarran

Evolutionary Relationship

Chuck-will's-widow and Great Hammerhead share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Chuck-will's-widow

LC — Least Concern

Great Hammerhead

CR — Critically Endangered

Trend: Decreasing ↓

Physical Characteristics

Attribute	Chuck-will's-widow	Great Hammerhead
Diet	—	Carnivore
Average Lifespan	—	40 years
Average Length	—	5.0 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Chuck-will's-widow

Habitat

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

Range

Distributed across Colombia, Norway, and Venezuela.

Great Hammerhead

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and flooded grasslands and savannas, among 5 distinct biome types spanning the Indomalayan and Neotropic and Oceanian realms. Populations are also found in montane and highland environments at higher elevations.

Range

Distributed across Colombia, Taiwan, and Venezuela. 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.

Great Hammerhead

The largest hammerhead shark species, great hammerheads reach up to 6 meters and are found in tropical and subtropical coastal waters worldwide. Their distinctive T-shaped head (cephalofoil) dramatically increases sensory surface area for electroreception, enabling them to detect buried stingrays through sand with exceptional precision — stingrays are a preferred prey. Critically Endangered, with populations declining dramatically due to highly valued fins and bycatch mortality.

Shared Countries

Both species can be found in 2 countries:

🇨🇴 Colombia 🇻🇪 Venezuela