Nighthawks Are Common in Summer
by Ro Wauer
A reader's call telling me that he had found a nighthawk nest alongside the Victoria Electric Cooperative reminded me that nighthawks is a subject that I had not yet written a nature note about. That is in spite of the common nighthawk being numerous throughout our area each summer. They normally arrive in the Golden Crescent by April and usually head south to their wintering grounds by the end of October. Rarely, an occasional bird may stay around during the winter months. But the vast majority of those that breed in North America, throughout Texas except for the Pineywoods, spend their winter months south of the border from southern Mexico to Argentina.
Most observations of common nighthawks are of those flying overhead, either over our fields and pastures or over our towns. Although most nests are placed on the ground, they have discovered that the flat roofs of our downtown stores offer suitable sites that are less susceptible to predators. Watch for nighthawks flying over our malls, larger stores and their parking lots. And identifying nighthawks in flight is easy because they have a very distinct flight that is erratic but swift and strong. They possess long pointed wings that are crossed by a wide whitish bar, barred underparts, white throat, short bill, and a long tail. But even more obvious is their voice, that has been described as an abrupt, nasal, buzzy sound, and when they dive in courtship or over a nesting site they will often emit a loud "peent" or "boom," produced by their vibrating primaries. Another of their names is "booming" nighthawk. Although they most often perch on the ground, it is not uncommon to find them sitting on a post, on a tree branch, or even on a high wire. Oftentimes one of these birds can be approached reasonably close as they may be sleeping with closed eyes.
Our common nighthawk is also known for its distraction displays. Although when approached by a predator or human being they may show mild aggression by rapidly opening and closing their huge mouth, a more serious display involves a broken-wing behavior. This typically involves spreading and dragging of a wing or tail, while slowly fluttering away from a nest or young as if injured, essentially leading an aggressor away. Then suddenly, just when it is about to be captured, it will fly off to safety.
Our common nighthawk is a member of the nightjar, or Caprimulgiformes, family of birds. There are 77 species of nightjars worldwide, but only nine species occur in North America: lesser nighthawk of the southwestern lowlands, from the Lower Rio Grande Valley west to California; Antillean nighthawk, found only at the southern tip of Florida; common pauraque, a Mexican species found in the U.S. only in the extreme southern tip of Texas; common poorwill, a small species found in the western half of the U.S.; chuck-will's-widow, common in the southeastern U.S.; whip-poor-will, a highland species of the eastern and southwestern mountains; buff-collared nightjar, known in the U.S. only from the arid canyons of southeast Arizona and southwest New Mexico.
All the nightjars are nocturnal, although the nighthawks will cruise about their breeding grounds during the daylight hours, especially at dawn and dusk and when feeding young. Almost any flying insect, as well as smaller birds, can be listed as prey species. The majority of their prey is captured in flight. Nightjars possess great wide mouths, and usually are able to grab their prey with ease. Their unique mouth has long suggested, as early as Aristotle's time, that they suck on goats, thus giving them the erroneous name of "goatsuckers," another name that has stuck.