Nighthawks

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

Mysterious Sounds of the Night…

Common Pauraque in Estero Llano Grande State Park, Hidalgo Co. Texas. Photo by David Marjamaa. Used by permission. 

Before dawn on March 16, we arrived at Bentsen-Rio Grande Valley State Park, outside of Mission, Texas. Our trip leader, Bill Rowe, had arranged for us to meet biologist and blogger Mary Gustafson at Bentsen to find the Common Pauraque. David Marjamaa, who took this great photo above, was part of the group too, along with me and five others. 
  

Nightjars are fascinating creatures, loaded with folklore, cryptic coloring, and evocative names. I presume that the name of the family, "Nightjar," comes from the fact that the typical calls of some species "jar the night," in the sense that the voice heard in the night is startling or has a disagreeable effect on the human listener. Of course, that "jar" is in the ear of the listener. I'm most familiar with one of Missouri's nightjars, the Whip-poor-will. Here's a beautiful recording by Lang Elliott. Its song is one of the most beautiful and haunting sounds in nature. A Whip-poor-will can belt out his clear, "whip poor WILL! whip poor WILL!" up to 400 times without a break. 

One breezy night in June, deep in the Ozark hills, a Whip-poor-will, perched on the ridge pole of our tent, came dangerously close to breaking that record. Tent-mate and guest blogger, J Bowen suggested solving the problem with a shotgun. I pretty much think that would be jarring in the night too, J! 

But I digress. We are talking about a different nightjar, the Common Pauraque. We walked down the road in the dark, hearing the "Quawk!" of Black-crowned Night-Herons amid the sounds of unfamiliar frogs and insects to me. First we strained to hear a distant Pauraque, then a bird answered, then many more. Mary used her industrial-strength flashlight to find the birds. We saw several near the road, making strange hops and short flights like long-tailed moths. Their eyes reflected the light of the beacon like torches.

No wonder these strange birds of the night have acquired so many tales, superstitions, and names. Their call sounds nothing like the English pronunciation of the name, "pah-RAH-kee." I surmised that it had originated from the Spanish, "¿Para que?"—"What for?" But it really doesn't sound like that either. Arthur Grosset pointed me toward an article from the Auk, 1948, that explains that the Mexican name for this bird in nearby Tamualipas is "Parruaca," pronounced "pahrrr-WAH-cuh," which more closely resembles the call. Evidently the word "Pauraque" is an incorrect English transcription. Pauraque's range just barely makes it into south Texas. It's found along both coasts of Central America, on in to northern South America, south to the northern edge of Argentina. In Central America, it's known as "Caballero de la Noche ("Gentleman of the Night") ; apparently, "el Caballero" is believed to be the Don Juan of birds. Nightjars are members of the family known as Goatsuckers, based on the ancient belief that the birds drank milk from goats. A pretty bizarre myth, but I guess those goats kicked up insects that the birds found tasty, and goat herders, frightened by dark, flying shapes in the night, assumed the worst. The scientific name for the family, Caprimulgidae, means the same thing in Latin. Of course, Spanish for Goatsucker would be Chupacabra, but that's another story. 
 
We heard another sound; one we couldn't identify at the time. Imagine some kind of hoarse, nasal baritone saying, ―Wowwwww! oo Wowww! It sounded a lot like the sound file below. What do you think it is?