Originally published in September/October 2004 edition of SD Conservation Digest.
Text and Photo by Doug Backlund
Wildlife Biologist, South Dakota Natural Heritage Program
To someone who has never heard a Chuck-will's-widow, just how this bird was named would seem puzzling. To anyone who has heard one, there is no question about how this species was named. An onomatopoeic name is defined as a name of a thing or action derived from a vocal imitation of the sound associated with it. Like the Common Poorwill and the Whip-poor-will, the Chuck-will's-widow is named for its call, a loud ringing call that can be easily heard over half a mile under good conditions.
All of these birds are in the family Caprimulgidae. The genus name Caprimulgus is a Latin form of the Greek words meaning "goat milker." Years ago many people believed that these birds flew at night to take milk from goats and the nickname "goatsucker" has stuck to the family of birds due to this ridiculous superstition. Most birds in the family Caprimulgidae are nocturnal but none of them take milk from goats. All are cryptic and very difficult to find. They blend in perfectly with their habitat and normally won't fly unless nearly stepped on. The most efficient method to find most species is to listen for their nocturnal calls.
Of the four species of caprimulgids that occur in South Dakota, the Chuck-will's-widow is the most enigmatic and the rarest. The Chuck-will's-widow is also the largest of the caprimulgids. Like others of its kind, the beak is small but the mouth is huge. These birds hunt insects while flying, scooping their prey from the air with the huge mouth. Chuck-will's-widows will even take small birds and bats when the opportunity arises. The historic breeding range is the southeastern United States, west to eastern Oklahoma and Texas and as far north as southern Iowa. In winter, the birds migrate to southern Florida, Cuba and other large islands of the Caribbean, and to Central America and northern South America. Leaving the tropics in late February and early March, the birds arrive on the breeding grounds by mid-March in Florida and by early May here in South Dakota. They return year after year to the same nesting areas in forested habitats with nearby clearings and openings that are used for hunting. Males call frequently as they patrol their territories just after sundown and before sunrise. On moonlit nights males may call most of the night.
Females normally lay two eggs. The eggs are laid on bare ground. The female is almost impossible to see when incubating, her camouflage is perfect. She won't flush unless nearly stepped on. Very little is known about most of the life history of these birds due to their ability to avoid detection. Only a few records exist of length of incubation, but it is thought to be about twenty to twenty-one days.
One interesting aspect of the nesting period is that the birds will move the eggs if they are disturbed. John James Audubon's account of this behavior is fascinating: "When the Chuck-wills-widow, either male or female (for each sits alternately) has discovered that the eggs have been touched, it ruffles its feathers and appears extremely dejected for a minute or two, after which it emits a low murmuring cry, scarcely audible at a distance of more than eighteen or twenty yards. At this time the other parent reaches the spot, flying so low over the ground that I thought its little feet must have touched it, as it skimmed along, and after a few low notes and some gesticulations; all indicative of great distress, takes an egg in its large mouth, the other bird doing the same, when they would fly off together, skimming closely over the ground, until they disappeared among the branches and trees. But to what distance they remove the eggs, I have never been able to ascertain; nor have I ever had an opportunity of witnessing the removal of the young. Should a person, coming upon the nest when the bird is sitting, refrain from touching the eggs, the bird returns to them and sits as before. This fact I have also ascertained by observations."
Audubon also wrote about the range of the Chuck-will's-widow as it was known in 1844: "Our Goatsuckers, although possessed of great power of wing, are particularly attached to certain districts and localities. The species now under consideration is seldom observed beyond the limits of the Choctaw Nation in the State of Mississippi, or the Carolinas, on the shores of the Atlantic, and may with propriety be looked upon as the southern species of the United States. Louisiana, Florida, the lower portions of Alabama and Georgia, are the parts in which it most abounds; and there it makes its appearance early in spring, coming over from Mexico, and probably still warmer climates."
The Chuck-will's-widow is expanding its range north and west. Proof of this expansion is found here in South Dakota. On May 16, 2000 Jeff Palmer and Rob Schenck stopped at our Farm Island Bird Banding Station to report a Chuck-will's-widow they had heard the night before. They were on their annual big day bird count, trying to find as many species of birds as possible in 24 hours. While listening for a Common Poorwill near Oahe Dam, they instead heard a Chuck-will's-widow. That night I went to the location and also heard the Chuck-will's-widow. Ricky Olson, Kenny Miller and I searched for several days trying to get a glimpse of the bird or find a nest but we had no luck. We finally decided it was a misplaced bird that would eventually wander on. Our hypothesis changed quickly on July 4th. My sister Susan Leach was bird watching in the area on that day and while walking a trail through the cottonwood forest she was suddenly besieged by a pair of birds that she thought were Chuck-will's-widows. The birds were apparently protective of a young bird nearby. We returned to the area that afternoon and found one recently fledged bird and two adults in the trees nearby, confirming the first breeding record of Chuck-will's-widow in South Dakota and a major extension of known breeding range. Amazingly, a pair of Chuck-will's-widow has been at this same site every year since.
If the Chuck-will's-widows continue to return to this nesting site, anyone who is interested in hearing the night calls of the big caprimulgid should be able to do so by listening from the Oahe Marina area at dusk. Best times of the year are May and early June. The male calls persistently in May as he patrols his territory in the twilight and well into the dark of night.
Like other nocturnal creatures that are seldom seen but often heard, birds like these stir imaginations. It is best to know them for what they really are, birds that have evolved amazing behavior, calls and camouflage that allows them to fill an ecological niche that other birds cannot. We can only speculate why Chuck-will's-widows are now nesting further north than the species did 160 years ago. The pair that nests in the cottonwood forest near Oahe Dam may be the harbinger of things to come.
Caprimulgids of South Dakota
Common Nighthawk The most common caprimulgid statewide, this species is frequently seen flying in the daytime hours. Well known for its spectacular aerial display. Also called the bullbat.
Common Poorwill Locally common in the west and around the edges of the Black Hills. Strictly nocturnal and very secretive, but sometimes seen on roads at night. Poorwills have a red eyeshine. The species is named for its call.
Whip-poor-will Nests in southeast South Dakota in river bottom forests. Migrants may be seen statewide, but are rare and difficult to locate. Strictly nocturnal. The species is named for its call.
Chuck-will's-widow The rarest caprimulgid in South Dakota. Normally found in the southeastern United States with a few nesting season records in Nebraska, Iowa, and now South Dakota. The species is named for its call.