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Common nighthawk

Common nighthawk

Chordeiles minor. By Rob Roberts

This story is featured in Montana Outdoors July-August 2017 issue

Last summer while hiking on Missoula’s Waterworks Hill, watching a storm approach, I was nearly knocked over by a thunderclap and “whoosh” by my head. When it happened again, I looked skyward and saw a common nighthawk deftly navigating the gusting wind and making it clear that it wanted no part of me on that weather-beaten patch of stunted lupine.

I later discovered two fuzzy, motionless young in the same spot—only alerted to their presence when their mother flushed from nearly under my feet and went flapping and hopping down the hillside. Thereafter watching from afar, I became transfixed by these spirited masters of air, camouflage, and deceit.

Identification 
The common nighthawk is a dark, medium-size bird with a short bill and long, pointed wings, resembling a boomerang with a head. Neither a hawk nor strictly nocturnal, it is often seen at dawn and dusk making agile and erratic flight patterns with loops and dives as it hunts for winged insects. Its large, gaping mouth allows the nighthawk to efficiently scoop up prey, much like an avian version of a whale shark grazing the ocean for krill. Nighthawk relatives in Montana include the common poorwill and eastern whip-poor-will. The common nighthawk is differentiated by its white throat patch and white bars near the end of its wings, as well as the male’s  distinct, nasally “peent” call while in flight.

Scientific name
The genus name Chordeiles—from the ancient Greek khoreia, a type of dance with music, and deile, “evening”—refers to the nighthawk’s graceful twilight flight. The specific minor is Latin for “smaller.” An interesting side note: Chordeiles is a genus in the family Caprimulgidae, which includes more than 80 species of birds worldwide, commonly called nightjars, bullbats, or goatsuckers. Caprimulgidae is derived from the Latin caper or “goat” and mulgeo or “extract milk,” from an ancient superstition that nightjars raid farmsteads under cover of darkness and suckle nanny goats.

Distribution, Migration, and Habitat
The common nighthawk is found throughout the continental United States and across Montana. These birds make one of the longest migrations of any North American bird, up to 4,000 miles, and are one of the last to arrive in spring in the lower 48 states. Individuals reach Montana from wintering grounds in southern South America by early to mid-June. They prefer open areas like grasslands or forest clearings, but will take up residence in farm fields, beaches, rock outcrops, or anywhere they can find abundant insects and a water source.

Camouflage 
Nighthawks have cryptic plumage, which makes them nearly invisible in trees or on the ground during daylight. Splotches or bars of gray, brown, and white over a black base help the birds disappear into a background of leaves, bark, and grass. They often sit parallel to a branch, rather than across it like most birds, looking much like a branch stump or leaf cluster.  

Distraction display
The nighthawk is a ground nester, laying two pale olive and brown speckled eggs in an open patch of dirt, gravel, or rock. The female occasionally leaves her eggs to feed. She also leaves the nest when a passerby gets too close. Much like a killdeer, she tries to confuse potential predators by flapping her wings and acting lame while leading the intruder away from the nest, behavior known as a distraction display. To avoid revealing the nest location, she will only return when the threat has been lured far away. 

Kaboom
With a sharp nosedive, the male nighthawk will swoop down toward a predator and flare at the last second, producing a sharp “boom” or growl as the wind rushes over its wings and vibrates the primary feathers.  The male employs these same aerial acrobatics to dive-bomb females during courtship displays, in what seems like a contrary way to woo a prospective mate.  

Conservation 
Common nighthawks are widespread and abundant in Montana. In much of the rest of the United States, however, populations are declining. Biologists say declines are likely due to widespread pesticide use to control mosquitoes, and reductions in nesting areas on gravel-topped roofs replaced by rubber liners or asphalt shingles. The loss of open areas and clearings due to urban development, reforestation, and fire suppression may have led to additional habitat loss, avian scientists say.Bear bullet

Writer Rob Roberts lives in Missoula.

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