Birds often get their common names for many reasons: what they look like, where they live, or the sounds they make. A few even sing their own name in their song. Three of them are the Eastern Whippoorwill (Antrostomus vociferus), the close cousin, Chuck-will’s-widow (Antrostomus carolinensis), and the Common Poorwill (Phalaenoptilus nuttallii). Their song, heard mostly in the evening and night hours, is a distinctive whip-poor-will!
Masters of disguise
Whippoorwills and their related species belong to a family of birds called the nightjars (Caprimulgidae) and are mostly active at night. The Eastern Whippoorwill is a medium size nightjar, measuring between 8 and 10 inches long from beak to tail. It has a short bill and long, rounded wings and tail. Male birds have a white patch under the throat and white tips on the outer tail feathers. The white tips on the tail feathers are used in courtship displays and to distract potential predators away from their eggs and young.
Whippoorwills are masters of disguise, especially during the day. Their plumage is a combination of browns and grays with lighter streaks, which gives them the appearance of dead leaves and bark. This is critical in protecting them against predators.
Their mouths are short and wide, which aids them in catching insects on the wing. They have large eyes, which are useful for finding prey in dim light. Another distinctive feature whippoorwills have is their “bristles” – long, thin feathers around the mouth that help funnel flying insects into their waiting mouths.
Whippoorwills prefer heavily forested areas with sparse undergrowth, often located near clearings and pastures. These areas provide optimum foraging habitat for insects and cover for adults and young birds. During the day, they will often perch on the ground or parallel to the tree branch (most birds perch perpendicular to the tree branch) to blend in with surrounding foliage.
Whippoorwills – like bats, chimney swifts and swallows – are insect-eating machines, which makes them valuable allies in controlling pests like mosquitoes and gnats. At dusk, the whippoorwill takes to the air, flying close to the ground with its short, wide beak opened wide to catch a variety of insects.
When it gets too dark to see their prey, whippoorwills stop hunting and will resume just before dawn. When a full moon is present, whippoorwills may use the light to their advantage and spend all night feeding. These birds can sometimes be observed along dirt roads at night taking dust baths to get rid of parasites.
Whippoorwills are rarely seen, yet often heard. They sing at a rate of one call per second and can call continuously for a long time. A researcher once documented 1,088 calls in a row by a particularly persistent bird. Folks not used to the sound of the whippoorwill’s continuous call often find it monotonous and sleep depriving. For others, it is a natural lullaby indicative of the nighttime evening landscape.
Breeding takes place during the late spring and into summer, depending on the species’ location. Male whippoorwills use their call to attract a female, establish a territory, and challenge any competition from other males. Whippoorwill courtship involves several displays, such as head bobbing and purring by the male as he circles the female and shows her the large white patches on his tail. If the female likes his courtship maneuvers, the birds mate.
Whippoorwill females typically lay two eggs at a time, which are incubated for about three weeks. After hatching, the young develop quickly. They lose their down and develop streaked feathers to help keep them hidden from potential predators. Both parents help care for the young, feeding them regurgitated insects.
Whippoorwills do not build an actual nest, and instead opt for a comfortable spot on the ground among fallen leaves or debris. Young whippoorwills are free to move around on the forest floor, which they do frequently to avoid predators. The male parent will attempt to distract intruders by hovering almost vertically and spreading its white-tipped tail feathers.
The young fledge in about 20 days. Female whippoorwills will sometimes start a second brood before the first one has fledged, increasing the chances that more of the young will survive.
An interesting characteristic of the whippoorwill’s breeding biology is how it times the hatching of its eggs. These birds will synchronize their breeding patterns with the lunar cycle so that the young hatch at or near a full moon. The full moon attracts more activity from insects and improves hunting success, critical for feeding new, hungry little mouths.
Although whippoorwills are widespread, their numbers appear to be declining. Like many other species of forest-dwelling birds, deforestation is thought to be a major cause of their decreasing populations. Whippoorwills prefer not only forest habitats, but forests without a lot of understory plants (shrubs, small trees, etc.). Forests of this type often depend on naturally occurring fires to reduce the low-growing plants and brush, and fire suppression in many areas has resulted in loss of this particular kind of habitat.
Other potential causes of the whippoorwill population decrease include collisions with vehicles, declines in food sources, preying feral dogs and cats, and invasive species.
There are a few simple ways the rural landowner can help restore whippoorwill numbers, though. Prescribed burning is one technique used to help regulate populations of plant and animal species by way of clearing out unwanted pests and overgrown vegetation. Properly managed grazing of livestock in forested areas is another way to improve and maintain whippoorwill habitat and helps ensure their nighttime serenade remains a part of our wildlife heritage. As with most wildlife, good habitat management can help maintain and restore whippoorwill numbers.
Far and Wide
The Eastern Whippoorwill is found throughout the eastern and central United States and southern and central Canada. The Mexican Whippoorwill (Antrostomus arizonae) is found in the southwestern United States, Mexico and into Central America. At one time Eastern and Mexican Whippoorwills were considered one widely spread species. However, noted differences in the birds’ calls, egg color and DNA resulted in a split between the two different species.
Northern species of the bird winter along the southern coasts of the U.S., Mexico and Central America. In the Deep South, the whippoorwill is usually replaced by the closely related and larger Chuck-will’s-widow, whose call is also true to its name. The smaller Common Poorwill is found mostly in the western U.S. and into Mexico. It is one of the few bird species known to hibernate in the winter rather than migrate.
John is a retired community college instructor. He now works as a vector control entomologist for the Mobile County Health Department. He lives in Irvington, Alabama with his wife, daughter, granddaughter, and several animals including dogs, cats, chickens, fish and a bearded dragon.