Common Nighthawk, Chordeiles minor
Note: this post, while published, is a work in progress, as are all posts in this series, My Photo Life List. My goal is to photograph every species of bird that is seen on a regular basis here in Michigan, working from a list compiled by the Michigan chapter of the Audubon Society. This will be a lifelong project, that I began in January of 2013, and as I shoot better photos of this, or any other species, I will update the post for that species with better photos when I can. While this series is not intended to be a field guide per se, my minimum standard for the photos in this series is that one has to be able to make a positive identification of the species in my photos. The information posted here is from either my observations or the Wikipedia, the online free encyclopedia, however, I have personally shot all the photos appearing in this series.
Common Nighthawk, Chordeiles minor
The common nighthawk (Chordeiles minor) is a medium-sized crepuscular or nocturnal bird within the nightjar family, whose presence and identity are best revealed by its vocalization. Typically dark (grey, black and brown), displaying cryptic colouration and intricate patterns, this bird is difficult to spot with the naked eye during the 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 that 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 to 25 cm (8.7 to 9.8 in) long, displays a wing span of 51 to 61 cm (20 to 24 in) weighs 55 to 98 g (1.9 to 3.5 oz), and has a life span of 4 to 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 3,000 m (9,800 ft). 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 adapted 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.
During migration, common nighthawks may travel 2,500 to 6,800 kilometres (1,600 to 4,200 mi). They 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 is one of the North America’s longer migrations. The northbound journey commences at the end of February and the birds reach destinations as late as mid-June. The southbound migration commences mid-July and reaches a close in early October.
There are no differences between the calls and song of the common nighthawk. The most conspicuous vocalization is a nasal peent or beernt during even flight. Peak vocalizations are reported 30 to 45 minutes after sunset.
A croaking auk auk auk is vocalized by males while in the presence of a female during courtship. Another courtship sound, thought to be made solely by the males, is the boom, created by air rushing through the primaries after a quick downward flex of the wings during a daytime dive.
In defense of their nests, the females make a rasping sound, and males clap their wings together. Strongly territorial males will perform dives against fledglings, females and intruders such as humans or raccoons.
Frequent flyers, the long-winged common nighthawk hunts on the wing for extended periods at high altitudes or in open areas. Crepuscular, flying insects are its preferred food source. The hunt ends as dusk becomes night, and resumes when night becomes dawn. Nighttime feeding (in complete darkness) is rare, even on evenings with a full moon. The bird displays opportunistic feeding tendencies, although it may be able to fine-tune its meal choice in the moments before capture.
Vision is presumed to be the main detection sense; no evidence exists to support or refute the use of echolocation. The birds have been observed to converge on artificial light sources in an effort to forage for insects enticed by the light. The average flight speed of common nighthawks is 23.4 km/h (14.5 mph).
The common nighthawk breeds during the period of mid-March to early October. It most commonly has only one brood per season, however sometimes a second brood is produced. The bird is assumed to breed every year. Reuse of nests by females in subsequent years has been reported. A monogamous pattern has also recently been confirmed.
Courting and mate selection occur partially in flight. The male dives and booms in an effort to garner female attention; the female may be in flight herself or stationary on the ground.
Copulation occurs when the pair settles on the ground together; the male with his rocking body, widespread tail wagging and bulging throat expresses guttural croaking sounds. This display by the male is performed repeatedly until copulation.
The preferred breeding/nesting habitat is in forested regions with expansive rocky outcrops, in clearings, in burned areas or in small patches of sandy gravel. The eggs are not laid in a nest, but on bare rock, gravel, or sometimes a living substrate such as lichen. Least popular are breeding sites in agricultural settings. As displayed in the latter portion of the 20th century, urban breeding is in decline. If urban breeding sites do occur, they are observed on flat gravel rooftops.
It is a solitary nester, putting great distances between itself and other pairs of the same species, but a nest would more commonly occur in closer proximity to other species of birds.
Females choose the nest site and are the primary incubators of the eggs; males will incubate occasionally. Incubation time varies but is approximately 18 days. The female will leave the nest unattended during the evening in order to feed. The male will roost in a neighbouring tree (the spot he chooses changes daily); he guards the nest by diving, hissing, wing-beating or booming at the sites. In the face of predation, common nighthawks do not abandon the nest easily; instead they likely rely on their cryptic colouration to camouflage themselves. If a departure does occur, the females have been noted to fly away, hissing at the intruder or performing a disturbance display.
The eggs are elliptical, strong, and variably coloured with heavy speckling. The common nighthawk lays two 6–7 g (0.21–0.25 oz) eggs per clutch; the eggs are laid over a period of 1 to 2 days. The female alone displays a brood patch.
The chicks may be heard peeping in the hours before they hatch. Once the chicks have broken out of the shells, the removal of the debris is necessary in order to avoid predators. The mother may carry the eggshells to another location or consume a portion of them. Once hatched, the nestlings are active and have their eyes fully or half open; additionally they display a sparing cover of soft down feathers. The chicks are semiprecocial. By day 2, the hatchlings’ bodily mass will double and they will be able to self-propel towards their mother’s call. The young will hiss at an intruder.
The young are fed by regurgitation before sunrise and after sunset. The male parent assists in feeding fledglings and will also feed the female during nesting. No records exist to support a parent’s ability to physically carry a chick.
On their 18th day, the young will make their first flight; by days 25–30, they are flying proficiently. The young are last seen with their parents on day 30. Complete development is shown between their 45–50th day. At day 52, the juvenile will join the flock, potentially migrating. Juvenile birds, in both sexes, are lighter in colour and have a smaller white wing-patch than adult common nighthawks.
Like other members of the caprimulgid clan, the nighthawk’s ground nesting habits endanger eggs and nestlings to predation by ground carnivores, such as skunks, raccoons and opossums. Confirmed predation on adults is restricted to domestic cats, golden eagles and great horned owls. Peregrine falcons have also been confirmed to attack nighthawks as prey, although the one recorded predation attempt was unsuccessful. Other suspected predators are likely to attack them, such as dogs, coyotes, foxes, hawks, American kestrels, owls, crows and ravens and snakes.
On to my photos:
These images were shot way back in the spring of 2013, in northeastern Michigan while I was on vacation. I had hoped to get better images, or to catch one perched, but I haven’t been lucky enough to do so.
This is number 208 in my photo life list, only 142 to go!
That’s it for this one, thanks for stopping by!