Eastern Whip-poor-will Life History

Habitat

Eastern Whip-poor-wills breed in dry deciduous or evergreen-deciduous forest with little or no underbrush, close to open areas. The forest types they use include pine-oak with juniper, pine plantations, pine flatwoods, northern hardwood forests, low-elevation white pine, oak, aspen, birch, and scrubby woodlands with pitch pine, scrub oak, and hickory. They seem to avoid large tracts of uninterrupted forest with dense canopy. Their migration habitat is similar to their breeding habitat. In winter, Eastern Whip-poor-wills prefer broadleaf tropical or subtropical forest near open areas.Back to top

Food

Eastern Whip-poor-wills feed exclusively on insects, including moths, scarab beetles, click beetles, long-horned grasshoppers, stoneflies, ground beetles, carrion beetles, tiger moths, ants, bees, wasps, fireflies, long-horned beetles, measuringworm moths, owlet moths, weevils, and scavenger beetles. They start foraging 30 minutes after sunset and continue until it gets too dark to see their prey. At first light they resume feeding, stopping about 40 minutes before sunrise. When the moon is bright enough, they may hunt all night long. During cold, rainy weather they will not try to forage. Whip-poor-wills perch in trees (or sometimes on the ground) and make short sallies to snag insects up to 15 feet off the ground, or they may stay out on longer insect-catching flights. Their enormous mouths allow them to swallow insects up to two inches long. They sometimes search rotten logs and leaves for ants, caterpillars, beetles, worms, and other insects. Back to top

Nesting

Nest Placement

The female Eastern Whip-poor-will lays her eggs directly on the leaf litter of the forest floor, usually on the north or northeast side of a small herb, shrub, or seedling that will shade the nest from the hot afternoon sun. Whip-poor-wills occasionally nest on bare ground, sand, or decayed wood. It’s not known whether males or females choose the site.

Nest Description

Whip-poor-wills build no nest, though the weight of the incubating adult may eventually create a slight hollow in the leaf litter. Despite the absence of nest material, the eggs, nestlings, and adults are all so well camouflaged that they are extremely difficult to see.

Nesting Facts

Behavior

Eastern Whip-poor-wills are nocturnal birds with loud, distinctive voices. At night they fly slowly and silently, often wheeling around 180 degrees in between wing flaps. When nesting or roosting, whip-poor-wills spend the day sitting motionless, becoming active only at dusk. They can fly nearly vertically when chasing insects. They usually forage in the semidarkness of early morning and early evening, but on moonlit nights they chase moths and beetles all night long. Whip-poor-wills appear to time their nesting so that chicks will hatch about 10 days before the full moon, when the parents have more time (and moonlight) to catch food for them. They regurgitate insects for their nestlings, which may move from the nest site within days of hatching if a predator comes to call. At about eight days old, the young molt into highly camouflaged plumage and the female leaves them in the care of the male, often starting a new clutch of two eggs nearby within the territory. The male establishes and maintains his territory by calling along the perimeter and by chasing off intruders while making aggressive calls and hisses, with raised wings and mouth open. Males and females feign injury to lead predators away from the nest. Whip-poor-wills are generally solitary, forming loose flocks during migration.Back to top

Conservation

Eastern Whip-poor-wills are fairly common birds, but their numbers declined by close to 2% per year between 1966 and 2019, resulting in a cumulative decline of about 61% during that time, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 1.8 million and rates them 14 out of 20 on the Continental Concern Score, for a species showing steep declines and facing major threats. The main problem Whip-poor-wills face is the loss of open-understory forests. This can come from conversion of forest to crops, pasture, urbanization, or fire suppression leading to dense understories. However, some habitat may be created as abandoned farmland reverts to forest. Because Whip-poor-wills often fly over roads or sit on roadways while foraging, they are also vulnerable to collisions with cars. Precise numbers for this nocturnal species are difficult to obtain through daytime surveys—but anyone can contribute data via the Nightjar Survey Network.

Credits

Cink, C. L. 2002. Whip-poor-will (Caprimulgus vociferus). In The Birds of North America, No. 620 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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