UKBirds

Common Nighthawk

Chordeiles minor

The Common Nighthawk is a medium-sized crepuscular or nocturnal bird, whose presence and identity are best revealed by its vocalization. Typically dark (grey, black and brown), displaying cryptic colouration and intricate patterns, this bird becomes invisible by day. Once aerial, with its buoyant but erratic flight, this bird is most conspicuous. The most remarkable feature of this aerial insectivore is its small beak belies the massiveness of its mouth. Some claim appearance similarities to owls. With its horizontal stance and short legs, the Common Nighthawk does not travel frequently on the ground, instead preferring to perch horizontally, parallel to branches, on posts, on the ground or on a roof. The males of this species may roost together but the bird is primarily solitary. The Common Nighthawk shows variability in territory size.

This caprimulguid has a large, flattened head with large eyes; facially it lacks rictal bristles. The Common Nighthawk has long slender wings that at rest extend beyond a notched tail. There is noticeable barring on the sides and abdomen, also white wing-patches.

The Common Nighthawk measures 22-25 cm in length, displays a wing span of 21-24" / 54-61 cm, weighs 62-98 g, and has a life span of 4-5 years.

The Common Nighthawk may be found in forests, desert, savannahs, beach and desert scrub, cities, and prairies, at elevations of sea level or below to 12000 ft / 3600 m . They are one of a handful of birds that are known to inhabit recently burned forests, and then dwindle in numbers, as successional growth occurs over the succeeding years or decades. The Common Nighthawk is drawn into urban built-up areas by insects.

The Common Nighthawk is the only Nighthawk occurring over the majority of northern North America.

Food availability is likely a key factor in determining which and when areas are suitable for habitation. The Common Nighthawk is not well designed to survive in poor conditions, specifically low food availability. Therefore, a constant food supply consistent with warmer temperatures is a driving force for migration and ultimately survival.

It is thought that the bird is not able to enter torpor, although recent evidence suggests the opposite.

The Common Nighthawk will migrate by day or night in loose flocks; frequently numbering in the thousands, no visible leader has been observed. The enormous distance travelled between breeding grounds and wintering range displays one of the North America's longer migrations. The north bound journey commences at the end of February and the birds reach destinations as late as mid June. The south bound migration commences mid July and reaches a close in early October.

While migrating, these birds have been reported travelling through middle America, Florida, the West Indies, Cuba, the Caribbean and Bermuda, finally completing their journey in the wintering grounds of South America, primarily Argentina.

As aerial insectivores, the migrants will feed on route, congregating to hunt in marshes, rivers and on lakeshores. In Manitoba and Ontario, Canada, it is reported that during migration the Nighthawks are seen most commonly in the late afternoon, into the evening, with a burst of sunset feeding activities.

Additionally, it has been noted that during migration the birds may fly closer to the ground than normal; possibly foraging for insects. There is speculation that feeding also occurs at higher altitudes.

The Common Nighthawk winters in the South Americas, but distribution in this locale is poorly known due to difficulties in distinguishing the bird from the Lesser Nighthawk and in differentiating between migrants and over wintering birds. In some South and Central American countries, a lack of study has led to restricted and incomplete records of the bird. Records do support wintering in Ecuador, Peru, Bolivia, Brazil, Paraguay, Uruguay and Argentina.