Blane Klemek: Get out in the evening and look for whippoorwills and nighthawks
For as often as I’ve heard the whippoorwill’s delightfully incessant vocalization, I have only seen the actual bird once. It was many years ago while sharing a canoe with my 8-year-old sister who, at the time, was enjoying her first Crow Wing River canoe trip. On the weekend’s first nighttime campfire, a whippoorwill began its nocturnal chorus a few dozen feet from our tent.
With a flashlight in hand, the two of us crept together in the dark woods toward the bird’s namesake call, “whip’ poor-weel, whip’ poor-weel, whip’ poor-weel...” Repeating itself over and over again the bird called while we stepped cautiously forward, careful not to step on a dry twig and scare the bird away.
To my complete surprise, we soon discovered the bird sitting comfortably in a tiny spot on the forest floor. Even in the bright beam of an artificial light, the whippoorwill only momentarily ceased calling. Soon, as we stood still and watched the bird, it opened its wide mouth and shouted its name. We were thrilled.
Whippoorwills belong to the avifaunal family Caprimulgidae, sometimes commonly referred to as goatsuckers or nightjars. Some 83 species of this family exist worldwide, seven of which can be found in North America. Further still, only two caprimulgids occur in Minnesota: the whippoorwill and the common nighthawk.
Like other members of the family, the plumage of whippoorwills and nighthawks is cryptically patterned, making them nearly impossible to detect during the day, let alone at night, unless of course they’re observed in flight during the light of day. Possessing short legs, small feet, and small bills, goatsuckers make up for these anatomical deficiencies with large heads and enormous mouths. It is for this last feature that equips goatsuckers so wonderfully well for the lifestyles they lead.
Most of their prey is flying insects such as moths and mosquitoes, so having large and wide mouths enable these acrobatic and graceful flyers to easily capture insects on the wing. Additionally, whippoorwills and most other caprimulgiform birds have long bristles that grow around their bills. The bristles aid the birds in catching insects as well as protecting their eyes from inopportune encounters with insects.
When looking at a field guidebook of birds, whippoorwills and nighthawks, if not all North American goatsuckers, look nearly identical. But subtle differences separate the species if you look closer. While the whippoorwill, for example, has moderately broad and rounded wings, the nighthawk flies about on long, white-barred pointed wings. For sure, the nighthawk’s silhouette, which is very raptor-like, nearly that of a falcon, is often mistaken for a bird of prey. As such, its name is really a misnomer, for the nighthawk is neither a true nocturnal bird nor is it a hawk.
As captivating a sound as the call of the whippoorwill is in the dark of night, male common nighthawks also conduct performances worth mentioning. In the spring of the year, male nighthawks perform aerial flight displays above their breeding grounds that are accompanied by loud “booming” sounds.
I have observed this species on many occasions over the years, some of which have been quite memorable. A few years ago while fishing off the public water access dock on Hennepin Lake in Hubbard County, I was mesmerized by a congregation of nighthawks that suddenly appeared in the twilight sky from nowhere. At first there were only a few birds, but soon they were everywhere.
I watched as they flew in their typical erratic manner; darting this way, banking that way, diving downward — pitching, yawing — sometimes seemingly striking one another with their long and slender wings. Quitting fishing, I stood and observed the spectacle until my neck became sore. The birds were quite literally engaged in what could only be determined as a feeding frenzy. Insects of some kind were flying amongst the enormous flock, and these wide-mouthed birds, not unlike their whippoorwill cousins, were feeding mightily on the bounty.
Regarding the previously mentioned courtship flight and booming displays of male nighthawks, the birds accomplish the sounds in a very unusual, almost unthinkable, manner. When the bird reaches the proper altitude, he enters into an abrupt and steep dive. As the diving nighthawk nears the earth, he bends his wings downward seconds before coming out of the dive. Loud booms or clap-like sounds are produced as air rushes through the tips of his wings. Nighthawk calls, which are normally vocalized while in flight, are described as “peents,” similar to that of the American woodcock.
I’ve been fortunate to observe nighthawks perform their courtship booming sounds on one special occasion while conducting wildlife research work on the prairie grasslands of North Dakota. As I walked on a sprawling short-grass flat adjacent to a wetland, I became aware of a sound I had never heard before. Looking in the direction of its source, I noticed two nighthawks flying in the broad daylight of a sunny afternoon. It surprised me to see the birds since one normally observes them only at dusk and dawn. I soon figured out that their abrupt dives and recoveries were what — somehow — produced the curiously loud sounds.
Indeed, we are fortunate to have both whippoorwills and common nighthawks as summer residents here in northern Minnesota. Having just arrived here from their wintering grounds not long ago, both species are undoubtedly nesting at this time. And while the whippoorwill is more at home in forested areas replete with breeding and nesting habitat, the nighthawk is a bird adapted to both rural and urban dwelling. These unique species of special birds are fascinating to observe as we get out and enjoy the great outdoors.
(Klemek is the DNR Area Wildlife Supervisor in Detroit Lakes. You can contact him at firstname.lastname@example.org.)