While most birds are active during the day, certain species extend their songs and calls into the nighttime hours. This nocturnal activity can be a normal part of their behavior, reflecting adaptations to their environment or specific biological needs.
Birds That Vocalize After Dark
A variety of bird species contribute to the nighttime soundscape. Owls are perhaps the most recognized nocturnal vocalizers, with different species producing distinct calls. Great Horned Owls, for instance, are known for their deep, resonant “hoo-hoo-hooooo” hoots, which can travel long distances. Eastern Screech-Owls produce a descending, horse-like whinny or a monotonic trill. Barn Owls, widespread across continents, are identified by their shrill, harsh screams rather than hoots.
Nightjars are another group of birds prominently heard at night, known for their unique, repetitive calls. The Eastern Whip-poor-will, for example, repeats its name distinctly, often for hours, particularly during breeding season. Other nightjar species like the Common Nighthawk make a nasal “peent” sound, while the Large-tailed Nightjar has a monotonous series of “chonk” notes, resembling chopping wood. These birds are well-camouflaged and primarily insect-eaters, making their nocturnal vocalizations a key way to detect their presence.
Some typically diurnal birds, such as the Northern Mockingbird, also sing at night. Unmated male mockingbirds are particularly known for their extensive nighttime songs, which can include mimicking other bird species, and sometimes even sounds like car alarms. Other songbirds, including robins and thrushes, may also vocalize into the evening or night, sometimes influenced by environmental factors. Migratory birds also make contact calls during nocturnal flights to stay together and navigate.
Why Birds Sing in the Night
Birds vocalize at night for several biological and environmental reasons. For nocturnal species like owls and nightjars, nighttime is their active period, so vocalizing is a normal part of their communication for activities such as defending territory and attracting mates. Male owls project rhythmic hoots to alert other owls to their presence in a territory and to signal their health and suitability to potential female partners.
Attracting a mate is a primary driver for many birds singing at night, especially during the spring breeding season. Male birds often use their loudest and most complex songs to gain the attention of females. The quiet environment of the night allows their voices to carry farther without the interference of daytime sounds, making their songs more effective for courtship.
Communication during migration is another reason for nocturnal vocalizations. Many bird species migrate under the cover of darkness, and they use specific contact calls to stay together within their flocks. These vocalizations help them navigate and maintain social bonds, especially when visibility is low.
Environmental factors, particularly artificial light pollution and urban noise, can also influence nocturnal singing in typically diurnal birds. In urban areas, daytime noise can mask bird calls, prompting some diurnal species, like American Robins, to shift their singing to quieter nighttime hours. Artificial light, such as streetlights, can disrupt a bird’s natural circadian rhythm, tricking them into thinking it is daytime and causing them to sing when they would otherwise be resting.
Understanding Nocturnal Bird Calls
Understanding nocturnal bird calls requires distinguishing them from other nighttime sounds and recognizing their varying purposes. Many insects, such as crickets and katydids, produce high-pitched chirping or grinding noises by rubbing their body parts together. These sounds can be confused with bird calls, but insect vocalizations typically have a more mechanical or rhythmic quality. Other nocturnal animals, like frogs, can produce croaks or trills, and certain mammals might make barks, growls, or screeches.
Bird calls vary widely depending on their purpose. Territorial calls, like the hoots of an owl, are often loud and repetitive, serving to warn off intruders. Alarm calls are sharp and urgent, signaling a perceived threat. Contact calls, used by migrating birds or family groups, help individuals stay connected.
The sound’s quality, pattern, and repetition offer clues to the species and its message. For example, the distinct, onomatopoeic calls of nightjars often directly reflect their common names, aiding in identification. Paying attention to the specific cadence and timbre of the vocalization helps differentiate between various birds and other creatures of the night.