Owls are famous for their late-night hootenannies, but lots of other birds croon by moonlight, too. In fact, ecosystems around the planet host a surprising variety of night birds — from nightingales and mockingbirds to corncrakes, potoos and whip-poor-wills — whose voices can be as haunting as any hoot from an owl.
Most of these birds have been serenading night since prehistory, and their after-dark arias are now staples in nature's dusk-to-dawn soundtrack. If not for night birds, the anthem of evening in many places may be little more than traffic noise and crickets.
Nothing against crickets — they're talented musicians, too. But while crickets specialize in droning background music, many night birds are scene stealers. Without the daytime cacophony to compete against, they're free to shatter the relative silence of night with each bubbly whistle, ethereal trill or demonic shriek.
Like owls, these birds are often heard, not seen. That can make them difficult to identify, especially those with large and diverse repertoires. If you're bewitched by a hidden minstrel on a camping trip — or maybe bemused by one outside your bedroom window — here are a few clues to help you identify the artist:
Northern mockingbird (North America)
Mockingbirds are known to sing night and day, but most late-night crooners are bachelors. (Photo: Donald Hobern/Flickr)
It's 1 a.m. Could there really be a dozen bird species singing in your backyard? Maybe, but are they performing one at a time? And do you live in North America? If so, "they" are probably a single northern mockingbird, Mimus polyglottos, looking for love.
Northern mockingbirds are among Earth's best mimids — a New World family of birds known for uncanny mimicry skills. They normally imitate fellow birds like jays, orioles and hawks, but they're prolific mimics, and sometimes branch out to echo other familiar sounds, from frogs' croaks' to humans' creaky doors and car alarms.
A mockingbird can learn 200 songs in its life, which males arrange into seasonal set lists for fall or spring. (Both sexes sing, but males are often more conspicuous.) While they aren't exactly nocturnal, unpaired males may sing 24 hours a day in the breeding season — spring to early summer — especially during a full moon.
Unlike many night singers, northern mockingbirds aren't shy, often choosing easily visible perches like a high branch, post or wire. They're not hard to identify by sight, especially if you can see the long tail and white wing patches. Relying on sound can be trickier, but here's one example of a late-night mockingbird revue in Virginia:
Common nightingale (Europe, Asia, Africa)
Many people consider nightingale songs "the finest produced by any bird species," writes U.K. charity Wildscreen, with "mellow phrases, flute-like sequences or high-quality, rich notes" blended into robust ballads. Nightingales have long served as literary symbols for writers such as Homer, Ovid, Chaucer and Shakespeare, and in Victorian England, outdoor parties were sometimes held just to hear them sing.
The species breeds between April and July across North Africa, Europe, the Middle East and Central Asia, then migrates to tropical parts of Africa for winter. It's famously shy, and tends to sing from the safety of dense bushes or thickets. Only male nightingales sing — they can master more than 200 different songs — and those performing on spring and summer nights are bachelors hoping to woo a mate.
Common nightingales were once common in Britain, but they've been hit hard by habitat loss, with U.K. numbers falling 57 percent from 1995 to 2009. They're still abundant elsewhere, though, with as many as 41 million adults in Europe and 81 million across the Old World. Here's a clip of one singing at night in Germany:
Eastern whip-poor-will (North and Central America)
Whip-poor-wills sleep on the forest floor by day and sing their name by night. (Photo: Dominic Sherony/Flickr)
Like the Old World nightingale, the American eastern whip-poor-will has long inspired humans with its nocturnal opera. Many poets, authors, filmmakers and musicians have featured its name and/or call in their work, including Washington Irving, H.P. Lovecraft, Robert Frost, William Faulkner, Frank Capra and Hank Williams, to name a few. And for anyone who's heard a whip-poor-will's soulful song flowing through a forest, it's little wonder why this bird is a mascot of American summer nights.
During spring and summer, whip-poor-wills breed in deciduous or mixed forests across the Eastern U.S. and southern Canada. They covertly sleep on the ground by day, where their plumage blends in with leaf litter, then venture out to eat insects at twilight and on moonlit nights. Their name is onomatopoeia (vaguely) for their call, which males sometimes repeat for hours in breeding season. "The song may seem to go on endlessly," according to the Audubon Society, which notes that "a patient observer once counted 1,088 whip-poor-wills given rapidly without a break."
Here's an example recorded in western Vermont:
In addition to the eastern whip-poor-will, North America is also home to several related species like the chuck-will's-widow, common nighthawk and Mexican whip-poor-will. These are all part of a larger bird family known as "nightjars," which includes dozens of nocturnal species around the world.
Great potoo (South and Central America)
Like many nightjars, great potoos use camouflage to sleep in trees during the day. (Photo: Francesco Veronesi/Flickr)
In tropical forests from southeastern Mexico to Bolivia, the still of night is periodically broken by a slow, guttural groan, sort of like an angry cat. This is the call of a great potoo, one of seven potoo species *, all nocturnal insect-eaters from the neotropics. It hides in trees by day, using ridiculously good camouflage to mimic broken branches. Despite a resemblance to owls, it belongs to a different group of birds known as caprimulgiformes, along with whip-poor-wills and other nightjars.
The great potoo vocalizes mainly on moonlit nights, producing a "fairly loud, gruff BUAAaa" at well-spaced intervals, according to zoologist Steven Hilty. This brief call may not be a "song" in the technical sense, but it's still a unique example of how eerily enchanting night birds can be. Listen for yourself in this video from Brazil:
* Not to dwell too long on potoos, but it's worth seven seconds to hear another, very different-sounding member of this bizarre bird family. The common potoo makes "one of the most hauntingly beautiful sounds of the American tropics," according to the Cornell Lab of Ornithology, and it deserves a wild-card spot in this list:
European robin (Europe, Asia, Africa)
Robins naturally sing at dusk and dawn, but light and noise pollution can extend their hours. (Photo: Darren Bellerby/Flickr)
European robins tend to hold a territory, and thus keep singing, year-round. They aren't naturally nocturnal, but they are well-adapted to twilight, so they also tend to be the first birds singing at dawn and the last to stop after dusk. And since their timing is based largely on light levels, robins can be easily fooled by electric lights.
"In fact, the robin is the most common night-time songster in Britain's towns and gardens," writes the Royal Society for the Protection of Birds (RSPB), noting that insomniac robins in the U.K. are commonly mistaken for nightingales. Similar night-singing has also been reported in other non-nocturnal species such as blackbirds, but it seems especially prevalent among European robins.
As biologist Davide Dominoni told the BBC in 2015, urban lights may convince robins that daytime never ends — and their extra singing isn't necessarily harmless. "Singing is a costly behavior; it takes energy," he said. "So by increasing their song output, there might be some energetic costs." Reducing light pollution may help, although research has found daytime city noise can also drive robins to sing at night.
Here's what a European robin's song sounds like:
Great reed warbler (Europe, Asia, Africa)
Many reed and sedge warblers "sing extensively during the night" in breeding season, the RSPB writes, referring to an array of species in the genus Acrocephalus. These small, insect-eating songbirds range from Western Europe and Africa across Asia and Oceania, and some live as far east as Hawaii and Kiribati.
One widespread species, the great reed warbler, breeds throughout mainland Europe and Asia during spring and summer, then migrates to sub-Saharan Africa for winter. Males attract females with a powerful song that lasts anywhere from 20 seconds to 20 minutes nonstop, and can be heard up to 450 meters (about 1,500 feet) away. Here's a clip of one singing at night in a Japanese wetland, recorded in June 2015:
Black-crowned night heron (Americas, Europe, Asia, Africa)
Black-crowned night herons perform a variety of clucks, squawks and screams at dusk or later. (Photo: Allan Hack/Flickr)
Herons inhabit every continent but Antarctica, typically hunting small aquatic animals near wetlands or water sources. At least 65 species are recognized worldwide, some of which have good enough night vision to keep hunting after sunset. For seven species, however, the night life has been so lucrative they're now mostly nocturnal, forming a diverse, cosmopolitan group of birds known as night herons.
Night herons are small by heron standards, but that doesn't seem to hinder their hunting skills. One of the best-known species is the black-crowned night heron, an opportunistic feeder common across North America (including most of the U.S.) as well as South America, Africa and Eurasia. It can live in a wide range of wetlands, nesting in colonies but often foraging alone. Its staccato calls aren't exactly songs, but they nonetheless add spooky ambience to its habitats after dark, from various croaks and barks to a loud kwok! often heard at dusk or overnight:
Eurasian nightjar (Europe, Asia, Africa)
The Eurasian nightjar is an iconic voice of summer evenings across much of Europe, North Africa and Asia. Like whip-poor-wills and other nightjars, it's in the order of birds known as caprimulgiformes, derived from Latin for "goat sucker." An ancient myth suggests nightjars steal goat milk at night, but they don't. The belief apparently came from the birds' wide mouths and habit of feeding near grazing animals.
Nightjars actually use their wide mouths to eat insects, and to sing — mostly around dusk and dawn, according to the RSPB, but also sometimes overnight. The word "nightjar" refers to the male's loud jarring or churring call, which can contain as many as 1,900 individual notes per minute. Here's a 10-second example:
Black rail (Americas)
Rails are a diverse family of ground-dwelling birds, native to a variety of habitats on every continent but Antarctica. Many species seek refuge in marshes or forests with dense vegetation, including some known for distinctive nocturnal noises.
About the size of a mouse, the tiny black rail lives in coastal marshes in scattered parts of the Americas, with populations clustered in California, the U.S. Gulf Coast, the Caribbean and Chile. It's secretive and rarely seen, but often heard late at night with a piping ki-ki-doo call. Here's an example from Port Aransas, Texas:
This list is just a small sampling of birds that make noise at night. Around the world, many other species also live by moonlight, dabble in nocturnality or emit subtle sounds while migrating after dark. Here are a few more notable examples:
And, of course, that's still not owl.