Systematics
Traditionally, nightjars have been divided into two subfamilies: the Caprimulginae, or typical nightjars with about 70 species, and the Chordeilinae, or nighthawks of the New World with about 9 species. The two groups are similar in most respects, but the typical nightjars have rictal bristles, longer bills, and softer plumage. In their pioneering DNA-DNA hybridisation work, Sibley and Ahlquist found that the genetic difference between the eared-nightjars and the typical nightjars was, in fact, greater than that between the typical nightjars and the nighthawks of the New World. Accordingly, they placed the eared-nightjars in a separate family: Eurostopodidae.
Subsequent work, both morphological and genetic, has provided support for the separation of the typical and the eared-nightjars, and some authorities have adopted this Sibley-Ahlquist recommendation, and also the more far-reaching one to group all the owls (traditionally Strigiformes) together in the Caprimulgiformes. The listing below retains a more orthodox arrangement, but recognises the eared-nightjars as a separate group. For more detail and an alternative classification scheme, see Caprimulgiformes and Sibley-Ahlquist taxonomy.
Subfamily Chordeilinae (nighthawks)
- Genus Nyctiprogne (2 species)
- Genus Podager - Nacunda Nighthawk
- Genus Lurocalis (2 species)
- Genus Chordeiles (5 species)
Subfamily Caprimulginae (typical nightjars)
- Genus Nyctidromus - Pauraque
- Genus Phalaenoptilus - Common Poorwill
- Genus Siphonorhis (2 living species)
- Genus Nyctiphrynus (4 species)
- Genus Caprimulgus (some 40-50 species, including the European Nightjar)
- Genus Antrostomus (11 species)
- Genus Macrodipteryx - Long-primaried nightjars (2 species)
- Genus Hydropsalis (2 species)
- Genus Uropsalis (2 species)
- Genus Macropsalis - Long-trained Nightjar
- Genus Eleothreptus - Sickle-winged Nightjar
Also see a list of nightjars, sortable by common and binomial names.
Read more about this topic: Nightjar