Common nighthawk
The Common nighthawk (Chordeiles minor) is a medium-sized, crepuscular bird in the nightjar family Caprimulgidae, characterized by its cryptic mottled grayish-brown plumage, long pointed wings with white wing bars, a notched tail, large eyes, and a wide gape for capturing flying insects.[1][2] It measures 22–24 cm in length, weighs 65–98 g, and is renowned for its erratic, bat-like flight during dawn and dusk foraging, as well as its distinctive "peent" call and booming aerial courtship dives produced by flexing its wing primaries.[1][2] Native to the Americas, the Common nighthawk breeds across much of North America and Central America—from Alaska to Panama—and migrates to winter in the lowlands of central and southern South America, undertaking journeys of 4,000–11,000 km, with occasional vagrants recorded in Europe.[1][2] It inhabits diverse open landscapes, including boreal forests, grasslands, savannas, woodlands, coastal dunes, and urban areas with flat gravel roofs or bare ground for nesting, often roosting on branches, posts, or rooftops during the day.[1][2] The species is primarily aerial insectivorous, feeding on flying ants, beetles, moths, and other insects caught in mid-air, and it may drink by skimming water surfaces.[1][2] Breeding occurs from May to August in northern populations, with pairs laying two eggs directly on the ground without a nest; incubation lasts 18–20 days, and fledglings become independent after 45–50 days, though southern populations may raise a second brood.[1] Males perform dramatic courtship dives to attract females, producing a hollow booming sound audible up to a kilometer away.[2] Solitary nesters, they are territorial during breeding but form loose flocks during migration.[1] Globally listed as Least Concern by the IUCN, Common nighthawk populations have declined significantly in some regions, with a 68% drop in southern Canada from 1970 to 2015 and a 12% decrease from 2005 to 2015 in southern Canada, attributed to habitat loss, pesticide use reducing insect prey, climate change, and urban development favoring smooth roofing materials over gravel.[3][4] In Canada, it is designated as Special Concern under the Species at Risk Act (updated from Threatened in 2007 as of 2018), with an estimated 270,000–900,000 adults in Canada remaining as of 2018, highlighting the need for ongoing monitoring and conservation efforts.[4]Taxonomy and nomenclature
Etymology
The scientific name of the common nighthawk, Chordeiles minor, originates from New Latin roots derived from Ancient Greek. The genus name Chordeiles is an irregular formation from chordē (string of a lyre or harp) and deilē (afternoon or evening), alluding to the bird's distinctive cry resembling a musical string sounded in the evening.[5] The specific epithet minor is Latin for "smaller," reflecting its relatively diminutive size compared to other nightjars in the Caprimulgidae family.[5] The common English name "nighthawk" dates to the early 17th century, first appearing in the 1611 King James Bible as a term for the European nightjar before being applied to New World species like Chordeiles minor; it combines "night" for the bird's crepuscular and nocturnal activity with "hawk" due to its swift, erratic flight resembling that of a hawk.[6] Another widespread colloquial name, "bullbat," emerged in the 19th century and refers to the bird's bat-like silhouette in flight and the booming, bull-like sound produced by air rushing through specialized wing feathers during courtship dives.[7] Regional North American names include "pisk," an onomatopoeic term of uncertain origin mimicking the bird's nasal call, particularly used in parts of the eastern United States.[8] Culturally, the common nighthawk contributed to Nebraska's early state nickname "Bugeater," adopted in the late 19th century to describe the bird's voracious insect-eating habits, which were seen as beneficial during times of agricultural hardship in the region.[9] In North American folklore, the species was often confused with the Eastern whip-poor-will (Antrostomus vociferus) by 18th- and 19th-century naturalists and locals due to overlapping habitats, similar nocturnal behaviors, and comparable calls, leading to shared myths such as omens of death or supernatural associations.[10]Classification and subspecies
The common nighthawk (Chordeiles minor) is classified within the family Caprimulgidae, known as nightjars or goatsuckers, which comprises crepuscular and nocturnal insectivorous birds characterized by their cryptic plumage and wide gape for aerial foraging.[11] Within this family, it belongs to the genus Chordeiles, which includes three extant species of nighthawks native to the Americas; the common nighthawk is the sister species to the Antillean nighthawk (C. gundlachii), with the lesser nighthawk (C. acutipennis) as the outgroup, based on molecular phylogenetic analyses.[11] The species has been recognized as a distinct entity, Chordeiles minor, since the early 19th century, following its initial scientific description by Johann Reinhold Forster in 1771 as Caprimulgus minor and subsequent placement in the genus Chordeiles by William John Swainson in 1827.[11] Early taxonomic treatments often lumped or split it from other nightjars, such as the eastern whip-poor-will (Antrostomus vociferus), due to superficial similarities in nocturnal habits, but 20th-century revisions based on morphology and vocalizations established its separation.[1] More recent genetic studies in the 21st century, including mitochondrial DNA sequencing, have confirmed the monophyly of the genus Chordeiles while suggesting potential polyphyly within the nighthawk subfamily Chordeilinae, prompting ongoing taxonomic reviews.[11] Nine subspecies of the common nighthawk are currently recognized, primarily distinguished by variations in body size, wing length, and plumage tone (ranging from paler, grayer forms in arid regions to darker, more mottled ones in humid areas), as defined through morphometric analyses in the early 20th century by ornithologists like Harry C. Oberholser.[11] These subspecies reflect clinal variation across the broad range from Canada to southern South America. The following table summarizes the recognized subspecies, their primary geographic distributions, and key distinguishing traits:| Subspecies | Geographic Range | Distinguishing Traits |
|---|---|---|
| C. m. minor | Eastern North America (from Newfoundland to Florida and west to Great Plains) | Nominate form; medium-sized (wing 200–210 mm); darker dorsal plumage with buff mottling; breast tawny.[12][11] |
| C. m. hesperis | Western North America (southwestern Canada to Baja California and Great Basin) | Larger (wing 215–225 mm); paler overall, with grayer tones adapted to arid habitats; reduced tawny on underparts.[12][11] |
| C. m. sennetti | South-central U.S. (Texas) to northeast Mexico | Intermediate size (wing 205–215 mm); slightly paler than minor with more extensive white on throat; found in coastal plains.[12][11] |
| C. m. howelli | Southwest U.S. (Arizona, New Mexico) to central Mexico | Smaller (wing 190–200 mm); darker with denser barring on underparts; breeds in open woodlands.[12][11] |
| C. m. henryi | Southwest U.S. (southern California) to north-central Mexico | Similar to hesperis but smaller (wing 195–205 mm); pale grayish plumage with fine vermiculation.[12][11] |
| C. m. aserriensis | Costa Rica (highlands) | Small (wing 185–195 mm); dark with rich buff tones on upperparts; restricted to montane areas.[11] |
| C. m. panamensis | Panama (lowlands) | Medium-small (wing 190–200 mm); paler ventral barring and lighter overall tone suited to Pacific slope.[11] |
| C. m. neotropicalis | Northern South America (Colombia to northern Peru) | Larger (wing 210–220 mm); very dark dorsum with heavy blackish mottling; adapted to humid forests.[11] |
| C. m. rufescens | Northern Venezuela and Colombia | Medium (wing 200–210 mm); reddish-buff tones on underparts, distinguishing it from neighboring forms.[11] |