Bird Files: Nighthawk Vacuums Insects in Sky

  • Flying Female Common Nighthawk. Photo: Alex Lamoreaux

October 3, 2014

For decades, the Common Nighthawk population has steeply declined on breeding grounds. In Pennsylvania, birders found them in 71 percent fewer locations when the most recent Pennsylvania Breeding Bird Atlas was published in 2010, compared to where they were spotted 20 years before. 

The Pennsylvania Breeding Bird Atlas map for sightings of the Common Nighthawks from 1983-1989. (see maps for all species)

The Pennsylvania Breeding Bird Atlas data for sightings of the Common Nighthawks from 2004-2009.

Right now, Common Nighthawks are preparing to leave North America for their wintering grounds in South America. But as October begins, you still might get to see the bird with the thick white bars under its wings and hear its distinctive peent call.

Earlier in the year, when it’s nesting season, you may get to witness the male’s dramatic courtship display as it dives headlong towards the ground, pulling up only at the last moment.

With that dive comes what many call a “boom,” a sound made as the wind rushes through the tips of his wing feathers.

Nighthawks are not really hawks at all. They belong to a group of birds called Nightjars. Europeans gave them that name because they associated the birds with the nocturnal nightjar bird there, which got its name because they found the bird’s calls to be jarring as it made its evening forays in the sky.

Nighthawks are also sometimes called goatsuckers, since older cultures believed that they swooped in at night to suck milk from goats.

Colorful folk tales aside, the Common Nighthawk’s main diet is insects which it is well equipped to capture with long, pointed wings that make fast, agile flight possible and a mouth that opens widely to efficiently grab its fast-flying prey.

Look and listen for them over insect-rich locations like lakes and rivers and in the city over brightly lit locations like sports stadiums and billboards.

If you do hear one, look for a sleek bird with striking white bars on its wings.

Bird calls for this segment provided by The Macaulay Library at the Cornell Lab of Ornithology, recorded by David S. Herr.

Image of the well-camouflaged Common Nighthawk at Petgill Lake in Squamish, British Columbia, Western Canada by Gavin Schaefer