The Nighthawk’s Trajectory

What the trajectory of Common Nighthawks tells us about the suburban landscape.

I’m an agnostic in all things but nighthawks, for with the bullbat I hold this belief: one cannot pursue the bird directly; rather, one can only seek a trajectory that may someday cross theirs. 

My faith in the bird was born amid their southward migration through Denver, Colorado, in September 2015. I’d gone looking for nighthawks in a place where and at a time when I thought it likely I might see one. Common Nighthawks are (mostly) crepuscular; they hunt for flying insects through dawn and dusk. Walking around central Denver’s Cheesman Park after sunset, eyes aimed upward, I found only brown bats. I sat a while, awaiting night, and watched these other things with wings. Then, I left.

In truth, I just readied to leave. I sat in my car and, though it was a Sunday and though it was evening, I compulsively checked my email. A (lengthy) message from my department chair at the University of Denver greeted me. Compulsively, I read it, though I believe one should neither mix time off with work nor birds with the same. Dusk gave way to night. The bats gave way to a still park.

At the end of the email, nighthawks. 

A trio, emerging from the nearby neighborhood, furiously pursued insects under the park’s streetlights. I left my car and followed them. Nighthawks, like swallows, feed on the wing, catching insects as they fly. They are strong, agile fliers. I have seen them cut upward, leaning backward as they do, in pursuit of prey. They make micro-adjustments that give them a “tipsy” appearance, as Pete Dunne puts it in his Field Guide Companion. To me, they appear confident in the air. Untouchable, even. Nighthawks always seem to be beyond their human-observer, even when approaching them—a twist of angles always cutting away. Unlike songbirds, which rarely fly directly at people, this trio chased their prey wherever it went, even if it meant flying directly at me. 

An arm’s length away, a nighthawk.  

Photo credit: "Nighthawk at Dusk (Centennial, Colorado)" by Jared Del Rosso
Nighthawk at Dusk (Jared Del Rosso)

One can only seek a trajectory that may someday cross the trajectory of a nighthawk. I spent this past summer seeking just that. I let my dogs lead me. I indulged every detour and delay. We turned home when they wanted to. We inspected dead ends. We doubled back on trails. We lingered when the dogs wanted to linger. We sat together in fields and on curbs. I suppressed my better judgement of where and when the birds would appear. By maintaining the appearance of not seeking nighthawks, I hoped I could fool serendipity into delivering them.

I did so to try to document the bird’s presence in Centennial, a southern suburb of Denver, during the bird’s nesting season. A mid-June sighting gave me hope. My dogs and I sought the birds above a buggy marsh at a local open space. The setting sun inspired the complex chorus of catbirds, blackbirds, and sparrows. But I missed a simpler sound: the buzz of the bird I sought, the distinct, nasal “peent” of a nighthawk. As dusk deepened, my dogs decided it was time to head back to our car. (One dog is afraid of the dark and what it means in Colorado: wild canids. The other is simply not much for walking.) I obliged, though I wanted to keep seeking. 

Nearer to the car, the dogs changed their minds, insisting I let them chase each other around me. Though leashed, the dogs sprinted circles. To keep myself from their tangle, I spun with them. Once, twice, then—and only because the dogs had chosen when to turn back and when to stop for play and when to turn me in the right direction—a nighthawk. 

I seek the nighthawk’s trajectory because I measure the world by this bird. They arrive in Colorado late in spring migration, just as that season tips toward summer. They leave before autumn begins whispering of winter. But the bird isn’t just a sign of the seasons. Their presence speaks of the complexity of our climate, the non-human world, and the human/non-human nexus. Obligate feeders on flying insects, the Common Nighthawk’s steep population decline over the past half-century may relate to broader declines in their prey, owing to pesticide use, the warming planet, and other factors. Nighthawks are losing habitat, too. Some of that habitat is their wild habitat of grasslands and forests. But they’re also losing built habitats in urban and suburban environments. Nighthawks use the flat, gravel-covered roofs of many urban buildings as nesting sites. Unfortunately for the birds, most new development forgoes gravel for other materials, such as rubber. (Patches of gravel, installed on flat roofs, are a potential compromise that may support nesting nighthawks. New Hampshire’s “Project Nighthawk” is experimenting with this.)  

The fate of Common Nighthawks is tethered to us, in ways that the fates of many non-human animals are. But it isn’t easy to observe our entangled destinies. Nighthawks are not like the chickadees that visit our feeders, the finches and phoebes that nest on nooks around our houses, the corvids that seem more at home around our homes than we do, or the hawks that hunt on our highways. Nighthawks nest on our skylines. They migrate at incredible heights, and the vast majority of these birds pass over our summer and fall activities without being noticed. By day, they disappear into trees, grasses, and rocks. Their cryptic feathering renders them invisible. If you’ve ever lucked into a sighting of a nighthawk on a tree, you know how easy it would be to overlook the bird. You also know that nighthawks don’t care that you’ve found them. Their faith in their camouflage, their use of difficult to access perches, and the fact that they have no need for daytime activity allows them to tolerate proximity to us. 

Photo credit: "Perched Common Nighthawk (St. Paul, Minnesota)" by Jared Del Rosso
Perched Nighthawk along the Mississippi River (Jared Del Rosso)

Ultimately, my trajectory and the Common Nighthawk’s did not intersect during their nesting season. Perhaps this is a sign of the species’ decline or of my neighborhood’s hostility, with our grassy lawns and dependence on pesticides, to the birds and their prey. Perhaps it is only that I have not yet found our shared trajectory. 

But I have learned something else from this effort. Pursue this uncommon bird, during the uncommon hours of dawn and dusk, and you will find the trajectory of other uncommon creatures. Those brown bats, one of which dropped me to my knees by hunting at the brim of my hat. A raccoon, ambling down a drainage ditch. A coyote, patrolling an undeveloped field. Fox kits, playfully hunting along a neighborhood path. Great Horned Owls, perched in suburban parking lots and cemeteries. A Mule Deer pair, cautiously watching the human animals who ride bikes, and toss baseballs, and walk dogs while seeking nighthawks in fields near riparian corridors.

This essay originally appeared on the Center for Humans & Nature’s blog.

Featured image by Kenneth Cole Schneider @

Neither night bird, nor hawk: The Common Nighthawk

I do not know that Common Nighthawks would recognize themselves in the name we’ve given them. Neither hawk nor night bird, the Common Nighthawk is largely crepuscular — most active at dawn and dusk — and rarely, if ever, at night. Nor it is a hawk, belonging, instead, among the Nightjars.

The scientific name of the Nighthawk’s genus — Chordeiles — suits it better. According to Merriam-Webster, the word’s origin refers to the bird’s evening call

New Latin, irregular from Greek chordē string of a lyre or harp + deilē afternoon, evening: from its cry at twilight

Wikipedia offers an even more evocative etymology, evoking both the bird’s calls and their buoyant flights.

The genus name Chordeiles is from Ancient Greek khoreia, a dance with music, and deile, “evening”.

According to the Oxford English Dictionary, the common name “Nighthawk” dates to the early-17th century and to the King James Bible. Then, the phrase likely was a pseudonym for the Eurasian Nightjar. It appears in Leviticus, among a longer list of birds that, for being abominations, shall not be eaten.

And these are they which ye shall have in abomination among the fowls; they shall not be eaten, they are an abomination: the eagle, and the ossifrage, and the ospray,

14 And the vulture, and the kite after his kind;

15 Every raven after his kind;

16 And the owl, and the night hawk, and the cuckow, and the hawk after his kind,

17 And the little owl, and the cormorant, and the great owl,

18 And the swan, and the pelican, and the gier eagle,

19 And the stork, the heron after her kind, and the lapwing, and the bat.

In the late-18th century, the name was applied to North America’s Nighthawk. According to OED (again), the earliest published use of the name “nighthawk” was in Jonathan Carver’s 1778 book, Travels through the Interior Parts of North America.

Carver miscategorizes the bird, clustering it with hawks. He writes,

The NIGHT HAWK. This Bird is of the hawk species, its bill being crooked, its wings formed for swiftness, and its shape nearly like that of the common hawk; but in size it is considerably less, and in colour rather darker. It is scarcely ever seen but in the evening, when, at the approach of twilight, it flies about, and darts itself in wanton gambols at the head of the belated traveller. Before a thunder-shower these birds are seen at an amazing height in the air assembled together in great numbers, as swallows are observed to do on the same occasion.

Despite identifying the Nighthawk as a hawk, Carver’s observations are consistent with my own. I have stood amid Nighthawks making “wanton gambols at the head of the belated” birder. (I wrote about this for the Center for Humans and Nature. You can read that essay, “The Nighthawk’s Trajectory,” here:

I have also seen great flocks of Nighthawks amid thunderstorms. Sometimes, they arrive as signs of incoming storms. Other times, they chase them. Presumably, the association of birds and storms carries another association — that the water leads to hatches of the bird’s prey (perhaps flying ants) or else causes prey to congregate in areas where Nighthawks might fetch them. I hope to not soon forget the dozens upon dozens of Nighthawks a friend and I saw feed amid a southern Colorado dry thunder storm.

Accordingly, I wrote a haiku for the birds.

dry thunder
a spray
of nighthawks

The meaning of the word “nighthawk” has become ever more expansive over the years. It carries shades of human meanings — to be a predatory person…at night.

The phrase has shed some of its negative connotations, now also simply meaning someone active at night. Though this meaning pre-dates Edward Hopper’s 1942 painting, “Nighthawks,” I suspect we owe the word’s lasting power to Hopper’s singular image.

I’d be remiss not to mention two other peculiar references that this bird’s name, has fed. Tom Wait’s album Nighthawks at the Diner is, no doubt, a nod to Hopper, even if a flock of Nighthawks over a desolate diner would be a site indeed.

And then there is this.

Historically, observers confused the Common Nighthawk with the Eastern Whip-poor-will. More on that in a later post. In the meantime, here’s a post on the Whip-poor-will and the history of its own name:

Featured Photo by vladeb @

From the Field #2: More Nighthawks, More Flying Ants

Last night, I arrived home from some errands around 6:30 PM to find a flock of Common Nighthawks feeding over my neighborhood in the southern suburbs of Denver. Two or three of the birds became several became a dozen then two then more still.

The birds flew wide laps around my neighborhood, occasionally streaming over my house. They were silent the entire time, as they fed on flying insects. The most likely prey were more flying ants. As I walked through my yard, I saw small insects taking flight. They stood out because they were not visiting, as the bees and flies and wasps and beetles do — my wildflowers. Rather, they seemed to float upward as they went.

I pursued a few of the insects, but most beat me to the sky. Finally, on a dog walk a bit later in the evening, I hawked one from its flight. (In truth, I cupped my hand in its path, causing it to land on my palm.) It was, indeed, a small flying ant.

The nighthawks looked dramatic in the late light of summer. Our western sun, as it dips toward the Rocky Mountains, is particularly strong and bright. The sun lit the nighthawks. Their white markings — their throats and underwings — shined.

The birds cast shadows on themselves, their long wings darkening their chests and flanks. This added to the drama of their flight, as they cut upward, backward, away, then back toward me.

I hope I never tire of this simple thrill — to be in the presence of these birds, who I barely understand. They seem to come out of nowhere. Not unlike the flying ants they pursue, which leave the rain-softened soil in late summer, nighthawks spend their days unseen. And where? Building tops? Perched on the cottonwoods lining the trails in Denver?

And then all at once, they arrive. Then all at once, they don’t.

In the Field #1: Common Nighthawks

On Friday night (August 12), a group of four or five Common Nighthawks (Chordeiles minor) joined a few swallows in feeding over my home and neighborhood. It’s always something when this happens — the birds flying relatively low, low enough to get good views (but not low enough for good photos).

The visit likely wasn’t a coincidence. Soon after the birds left, I spotted a few flying insects in my yard. They seem to be one of the nighthawks favored late-summer prey, flying ants, though I’m still working to confirm my tentative i.d.

According to the wonderful resource, Birds of the World (subscription required), a 1940 study of the stomach contents of 87 Nighthawks found that flying ants constituted about 25% of the mass of what the birds ate. Flying ants apparently emerge in late summer and, so, are a critical food source for migrating Nighthawks, not unlike late blooms (and feeders full of sugar water) are for migrating hummingbirds.

We’re in the early days of the Common Nighthawks’ southward migration. In past years, I’ve seen them in great numbers (for a suburban environment) in my neighborhood, encountering flocks of a dozen or two or three feeding over area parks. Here’s hoping this year brings the same.

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