Common Nighthawk are Not Hawks but Goatsuckers
Ro Wauer, May 18, 2003, The Victoria Advocate, © 2003
This common summertime bird is known by a number of names, including "booming nighthawk," due to its loud calls; and also "bullbat," because it flies at night and often is mistaken for a huge bat. One can usually hear this bird in the evening and early morning hours over its breeding grounds, where it makes deep dives, giving loud booming noises at the bottom of each dive. The calls also have been described as nasal "peents" or "beerp" sounds. The bullbat term is derived from its habit of flying at night and its bat-like flight. And during the nesting season, when feeding young, it also can be expected during the daylight hours.
Nighthawks are often improperly associated with hawks, probably because of their name, but belong to a completely different family of birds, the Caprimulgids or nightjars. Other North American nightjars include the lesser nighthawk of the arid Southwest; chuck-will's-widow, of the Southeast; whip-poor-will, of the northeast and West Texas mountains; common poorwill, found throughout much of the western United States; and common pauraque, the largest of the family and found only in extreme South Texas. A couple other family members, such as Antillian nighthawk and buff-collared nightjar, occur in the U.S. only in South Florida and extreme southwestern New Mexico and southeastern Arizona, respectively. All are characterized by huge mouths, used for capturing insects, and their nighttime activities.
The two most similar species are the common and lesser nighthawks that may actually overlap in some South Texas counties. The common nighthawk is the larger of the two, but size alone can be difficult to discern. Lesser nighthawks never dive or call like their larger cousins, but call is a low growling sound and they usually fly close to the ground. In flight, the smaller lesser nighthawk shows a white band across the wings very near the tip, while the white band of the common nighthawk is halfway between the wingtip and bend of the wing.
Both nighthawks are ground nesters, using a scrape on the ground or other flat surface, where they place two olive-white eggs. White the lesser nighthawk usually is found in wild areas, the common nighthawk has adapted very well to civilization. It even nests on flat roofs of various buildings, including malls. It is not unusual, therefore, to find these birds flying about mall parking lots in their search for insect prey. They typically fly high overhead where they chase down flying insects and capture them in their extremely wide mouth. They can be extremely acrobatic in their pursuit. They may even come to the ground when insect populations are more common there, especially when they are required to obtain addition prey to feed hungry young. Nighthawks are proven insect eaters, consuming mosquitoes and numerous other kinds of pests. One study revealed that one nighthawk stomach contained 2,175 flying ants. The adults will feed the nestlings by regurgitation.
Common nighthawks normally are present in the Central Gulf Coast region only from April into October. They then migrate southward to the Tropics, as far south as South America. They often travel in great numbers; there are records of flocks numbering almost 1000 individuals, "flying at high altitudes instead of flying in their typical erratic manner," according to Kent Rylander's book, "The Behavior of Texas Birds." We can often find numerous nighthawks resting on fence posts and wires during migration time.
Although nighthawks are most properly known as nightjars of the family Caprimuligidae, the term goatsucker comes from a legend that claims that these insect eaters suck milk from goats at night. Of the 67 known kinds of nightjars, worldwide, all are insect eaters only.