Home / Blogs / Longer than the Song of the Whippoorwill
May 10, 2021
An eastern whippoorwill (Antrostomus vociferous) perches on a tree branch in the eastern deciduous forest (Photo credit: birdsoftheworld.org).
Goatsuckers. Nightjars. Bullbats. Frogmouths. Potoos. Will’s-widows. While these names may conjure images of terrifying mythical creatures, they actually refer to species within the Order Caprimulgiformes, a group of nocturnal, insectivorous birds. Many of these bird species have evolved very distinctive morphological adaptations, resulting in a rather unique physical appearance. They have developed large eyes and wide mouths that aid in nocturnal hunting and flight. Their cryptic coloration and motionless ground-roosting behavior hides them from predators. Before these species were better understood, some unusual names and fables were developed in an attempt to describe their behavior and ecology. In Latin, Caprimulgus translates to ‘goatsucker’, or ‘goat-milker.’ The term was derived by Europeans that (incorrectly) believed that the European nightjar fed by milking goats during the night. It has also been suggested that these birds would capture the fleeing souls of the deceased. Others thought their repetitive night time songs would lead to insomnia. While the latter may be true for some, most of the stories surrounding these birds were purely fiction. Here in the Chesapeake region, we have multiple Caprimulgiform species, including the common nighthawk, the chuck-will’s-widow, and the eastern whippoorwill.
The eastern whippoorwill (Antrostomus vociferous) has a fairly widespread distribution throughout the Chesapeake region. It is also one of my favorite birds. I have spent many spring nights in the Pennsylvania forests falling asleep to the seemingly never-ending chorus of “whip-poor-will, whip-poor-will, whip-poor-will,” dreaming of the gobblers and trout I would pursue the next morning. For me, springtime in the Pennsylvania woods is synonymous with some very distinctive sounds and images. Choruses of spring peepers. Lady slippers, trilliums, and azaleas in bloom. Turkeys gobbling. Grouse drumming. Trout rising to feed on emerging insects. And of course, whippoorwills calling throughout the night. Not only is the song of the whippoorwill beautifully distinct, their ecology and behavior are also fascinating.
Synonymous with Spring (From Left to Right): Pink Lady-Slipper (Cypripedium acaule), Wild Brown Trout (Salmo trutta), Purple Trillium (Trillium erectum) (Photo credit: Jim Kauffman, Alliance for the Chesapeake Bay).
Whippoorwills are temporary residents of the eastern forests, spending their winters in the southeastern United States, Mexico, and Central America. When spring arrives, whippoorwills migrate north to exploit the seasonal abundance of insects here in our eastern forests, mate, and raise their young. They are completely nocturnal, feeding on insects they capture in flight. They have large, gaping mouths and oversized eyes, both adaptations that allow them to capture these flying insects at night. Feeding primarily at dawn and dusk, moths (including the large Saturniid moths) make up the bulk of the Whippoorwill’s diet. Whippoorwills have a tapetum lucidum, a layer of tissue within the eye that reflects light back through the retina, increasing the amount of light available to the eye’s photoreceptors. This feature is very distinct in the headlights of a vehicle at night. Most of the whippoorwills I have been lucky enough to see have been as a single glowing eye in the middle of a state forest gravel road.
A giant Saturniid Polyphemus moth (Antheraea polyphemus), a prey item of the eastern whippoorwill (Photo credit: Jim Kauffman).
Whippoorwills select wooded uplands for nesting and feeding and prefer habitats that include young components and small openings within early to mid-successional forests. This includes scrub oak and pitch pine ‘barrens,’ mixed woodlands, and forests with semi-open canopies. Males spend spring nights calling for receptive females, eventually forming a monogamous breeding pair. Males continue to sing throughout the spring to advertise their presence and defend their breeding territory. The whippoorwill is aptly named, as its repetitive, three-note song really does sound the way it is pronounced. And when I say repetitive, I mean it. Male whippoorwills seem to have unlimited energy, as they often sing constantly throughout moonlit spring nights. As ground-nesters, whippoorwills lay two eggs directly on the leaf litter without physically constructing a nest. Females incubate the nest, relying on cryptic, camouflage plumage and a low profile to avoid being found by predators. Females will typically remain on the nest, motionless, refusing to flush until almost stepped on.
A camouflaged female whippoorwill incubates her nest on the forest floor (Photo credit: nature.mdc.mo.gov).
For successful prey acquisition and nest success, whippoorwills depend on woodland habitats with just the right mix of forest components. Whippoorwills have evolved to exploit early to mid-successional forests with little herbaceous understory. This habitat type typically contains a less dense forest canopy, allowing moonlight to illuminate pockets within the forest where whippoorwills pursue flying insects at night. Young saplings, small pines, and scrub oaks provide coarse mid-story cover that aids in hiding nests from predators. Large clearcuts and fields with herbaceous vegetation are typically avoided. If too much herbaceous vegetation is present on the forest floor, whippoorwills can not find a suitable open area on the leaf litter to nest. Their coloration has evolved to blend in with a forest floor covered in leaves, not one that is dominated by grasses and forbs.
A clutch of whippoorwill eggs laid directly on the forest floor (Photo credit: abcbirds.org).
Over time, the early and mid-successional forests, barrens, and semi-open woodland habitats that whippoorwills depend on have decreased in distribution and abundance. This is due primarily due to forest succession, changes in forest composition, and a decline in the frequency of fire. Fires were once more common in the eastern forest, particularly in barrens and other upland habitats. Periodic fire created early and mid-successional forest and maintained semi-open canopies in areas where fire frequency was high. Due to fire suppression policies, many forests have reverted to old-growth with closed canopies and little shrub understory. The advance of invasive species within the eastern forest understory (like Japanese barberry) has also reduced the value of habitats utilized by whippoorwills. Forest fragmentation due to expanded agriculture, suburban development, and natural resource extraction has impacted whippoorwills by reducing the amount of contiguous forest available for food acquisition and rearing young. Fragmentation (and the removal of top-tier predators) has also increased populations of mesocarnivore ‘edge predators’ (like skunks, raccoons, opossums) that prey on whippoorwill nests. Declines in moth abundance may also be affecting whippoorwills. As a result, whippoorwill populations have recently declined throughout their range. Fortunately, forest managers are applying management practices that will benefit whippoorwills. This includes prescribed fire, invasive species control, and selective tree harvest.
Whip-poor-will from John James Audubon’s Birds of America (Photo: audubon.org).
There is something really magical about the song of the whippoorwill. It might be nostalgia for me, because I spent so many childhood nights listening to their never-ending midnight song just outside my cabin window. Or it might be the magic of hearing something so clearly that is so difficult to actually see. Or it could be what they represent; a symbol of healthy, natural forests that were once widespread throughout the Chesapeake region. If you have never had the privilege to hear the whippoorwill’s endless midnight song, please make it a point to spend some time in the whippoorwill woods this spring. Find a campground and pitch a tent, and let the local male whippoorwill sing you to sleep. John Denver said “I know he’d be a poorer man if he never saw an eagle fly.” Well I think that’s how I feel about the song of the whippoorwill. The Chesapeake spring would just be incomplete without it.
If you are interested in managing your forests for whippoorwills or other wildlife, please contact The Alliance for the Chesapeake Bay about forest management programs available in your area. By managing your woodlands for wildlife and future generations you have the opportunity to leave a legacy that lasts ‘Longer than the Song of the Whippoorwill.’
Pennsylvania Forests Projects Coordinator
(717) 517 8698
Forests for the Bay