Sunday, October 2, 2011


We could call it a "kettle," if they were hawks--a pretty good description of a flock where the individuals seems to boil from the top to the bottom over and over again. In that sense, I watched a kettle of Common Nighthawks over the dog park on September 20. I estimated at least 60 in the flock, but it could easily have been twice that. The kettle gradually moved west, the birds whirling and flashing like flakes in a snow globe. The birds never dropped as low as the tree tops, while below, a flock of migrating Green Darner dragonflies roiled in their own version of a kettle, 6 to 15 feet above ground. The Crossley ID Guide (Richard Crossley, 2011) mentions that they are often found along wooded streams, and the dog park is within sight of the Meramec River.

Nighthawks are not even close to being hawks, but they hunt on the wing, that is, they "hawk" for insects, and are most active in twilight. My dad used to call them "bullbats." If you use the word "bull" to mean "large or strong," they certainly would be large, strong bats, if they were bats. He told me they liked to hang around the lights at the ballpark and sometimes along the street. I used to see them in those places too as a kid, but I see fewer and fewer of them now flying erratically over towns. The Sibley Guide to Bird Life and Behavior, by David Sibley (2001), notes that Common Nighthawk populations have declined throughout their breeding range (p. 352). The breeding range covers most of the Canada and the US (excluding south and central California, Alaska, and areas near or north of the arctic circle), and the western portion of Mexico (excluding Baja California). Factors contributing to the decline include the use of insecticides, and the loss of open areas that they need for hunting and mating displays (Sibley).

Nighthawks don't build nests, laying their eggs on the ground in open, rocky areas. They have adapted to using flat roofs covered with gravel, but as these become less common and roofs insulated with smooth PVC coatings become the norm, nighthawks have lost an important resource. In her book 101 Ways to Help Birds, Laura Erickson (2006) discusses ways to accommodate nighthawk nesting sites (p. 169) by providing pads with gravel in shaded areas of flat roofs.

Besides their beautiful, haphazard flight, male nighthawks have an intriguing display. I heard it "in the wild" only once. I was sitting on the front stoop of a shop, enjoying a traditional St. Louis treat, a "concrete," when I heard it. Nighthawks had been flying overheard, calling with nasal, off-key notes, "beans...beans..." when I heard a sound that shouldn't have come from a bird. Greg Budney, audio curator of the Macaulay Library at Cornell, describes it as similar to "a truck roaring by, that suddenly disappears." Somewhere along the city street, a male nighthawk dove between the buidlings, creating that roar as wind passed through the long flight feathers. Perhaps he planned his display to take advantage of the echoes in the urban "canyon."

At the end of the recording below, you hear this mechanical sound. If you have 2 minutes, check out the video from Cornell's Lab of Ornithology which I embedded below it. Thanks to Bill Bouton for his great photo of a Common Nighthawk above, taken in northern California, and to Don Jones who recorded the species in New Jersey, and the Cornell Lab, all of whom licensed their work with Creative Commons.

You might also like:
Crossley ID Guide   
Macaulay Library of Animal Sounds
Mysterious Sounds of the Night


  1. Thanks so much for this post! I grew up watching nighthawks each night in suburban Chicago, as our house was across the street from what is now a forest preserve. I remember seeing a nighthawk sitting (nesting?) on top of my neighbor's chimney one year, but can't remember if it was for more than a day or not.

    I didn't know that their numbers were dwindling. Sad.

  2. Hi Alan, I'm finally getting around to replying to your comment. The nighthawk could have been nesting on the roof, but they do like to roost on posts, branches, and probably chimneys. They're such an interesting and beneficial species.

  3. You take such nice shots! That first picture looks so majestic, its such a good angle to show off its power. I was wondering what kind of binoculars you use for watching? Or do you just rely on your camera? I've been checking out the selection from The Sportsman's Guide's optics section on their binoculars page. I wanted to know if you had any recommendations as far as maybe a better dealer, or a brand you have come to trust, and what I should expect to spend on a solid pair. Thanks in advance and keep up the good work =)

  4. What a nice majestic though fine bird! Wonderful. I didn't know this bird before, thanks for the information Anne! I wish you a great Sunday!