A midsummer moon rises, the heat of the day dissipates, and the refreshing sounds arise from summer’s vespertine routines. In some lucky places in Wisconsin, that routine includes a bird with a song unfortunately known as “incessant.” A non-stop cacophony departs from rocky hillsides, like the bird is banging its head against the rock. And yet, somehow its song is beautiful in a kind of persistent and gritty way. You cannot help but love the eastern whip-poor-will.
Eastern Whip-poor-will, by American Bird Conservancy
A bird so vociferous that its Latin name coined it as such (Antrostomus vociferous) would seem to be easy to detect for monitoring purposes. Yet most birding occurs when there’s light, so for a project like Wisconsin’s second Breeding Bird Atlas, effort must be taken to bird during nocturnal hours. Other surveys like the Wisconsin Nightjar Survey focus specifically on gathering data about birds like the eastern whip-poor-will.
While the related chimney swifts and nighthawks steal the show in late-August through September, whip-poor-wills will (often) quietly make their migration to Mexico, Central America, and the U.S. Gulf Coast.
Barrens type habitat in northeastern Wisconsin, photo by Drew Harry
From my limited experiences hearing whip-poor-wills, I believe there’s something about their habitat that correlates to high quality natural areas. I’ve heard the birds in the Driftless, where oak forests with scattered prairie openings on steep south facing slopes still hang on despite years of fire suppression. I’ve heard them along bluffs on the Wisconsin River, where again oak-pine forests intermix with sandy prairie and barrens environments. And again, I’ve heard them on the bluffs above the Brule River in Northeast Wisconsin, on rocky talus slopes of an open Red Pine canopy. Perhaps the piece of information linking these areas is the species richness in the understories of these canopies, which is due in no small part to the historical (and sometimes current) effects of fire on the landscape. Fire maintains a scattered canopy and stimulates flowering and germination in the understory.
From “Preliminary Results of Nightjar Survey” at: wiatri.net
Note the high abundance in the Central Sands, Northeast Sands, and Northwest Sands: areas of dry soils, pine-oak forest, and prairies and barrens
For a bird like the whip-poor-will, these high-quality areas provide suitable breeding habitat. The birds do not even build a nest. With their excellent camouflage, they will simply lay eggs on the forest floor—another leaf in a sea of leaves.
Many birds overwinter in Florida, which happens to lead the nation in prescribed fire, burning almost 200,000 acres annually. While Wisconsin is roughly the same size, the average acres burned in a year is only about 40,000. The reliance of whip-poor-wills on disturbance regimes is apparent from multiple published papers. Canadian Breeding Bird Survey Routes with whip-poor-wills correlated with clearcuts and old field areas. Historically, the maintenance of open savannas and woodlands occurred through fire. Today, much of the habitat created for whip-poor-wills comes from forestry practices.
Breeding Bird Surveys in the United States have recorded a 75% decline between 1966 and 2015. An aerial insectivore, whip-poor-wills are also susceptible to apparent insect declines. At Faville Grove, the creation of prairie and the restoration of oak savanna habitat could provide suitable nesting for whip-poor-wills. It would be a delight to be kept up at night listening to their song.
Written by Drew Harry, Faville Grove Sanctuary land steward
Cover photo by Andy Reago & Chrissy McClarren
