The quiet hours of night often bring forth a surprising array of sounds from the natural world. Among these, the distinct vocalizations of birds can be particularly striking, sometimes manifesting as sharp, piercing screeches that capture human attention. These nighttime cries are a natural part of the avian world, serving various purposes for the birds that produce them. They offer a glimpse into the hidden lives of nocturnal and crepuscular species.
Common Nocturnal Screeching Birds
Various owl species are a frequent source of nighttime screeches. Barn Owls, for instance, are well-known for their raspy, harsh screeches or shrieks, which they frequently use as their primary call, especially males during flight. These sounds can be quite startling and are distinct from the typical hoots associated with other owls. Eastern and Western Screech-Owls, despite their name, typically produce whinnies and trills rather than a true screech. Their vocalizations can range from soft, quavering calls to a descending whinny.
Common Nighthawks, a crepuscular or nocturnal species, make a nasal “peent” or “beernt” sound while in flight. Male nighthawks also produce a unique non-vocal “boom” sound with their wings during courtship dives. This distinctive sound is created by air rushing through their primary feathers. Black-crowned Night Herons are also vocal after dark, emitting barking squawks, guttural notes, or raspy “woc-a-woc” calls, particularly when disturbed or around their nests. Yellow-crowned Night Herons also contribute with harsh squawks.
Reasons Behind Nighttime Screeches
Birds screech at night primarily for communication, fulfilling essential biological needs. One significant reason is mate attraction, especially during the breeding season in spring, when male birds vocalize loudly to showcase their fitness. The cover of darkness provides a quieter environment where their calls can travel further without daytime interference. This increased nocturnal vocalization helps them find partners.
Territorial defense is another key motivation for nighttime screeches. Birds use these sounds to warn other individuals to stay out of their established territory. Such acoustic marking is particularly effective in dense habitats where visual cues are limited. Additionally, these calls serve for general communication within a flock, between parents and their young, or as warnings about potential dangers. Alarm calls can alert others to the presence of predators.
Some diurnal birds may also vocalize at night due to environmental factors. Light pollution, such as streetlights, can confuse their internal clocks, leading them to sing as if it were dawn or dusk. Noise pollution during the day can also compel some birds to save their singing for the quieter nighttime hours.
Identifying the Sound Source
Identifying the specific bird making a screeching sound at night involves careful observation and the use of available resources. Noticing the exact time of night, the duration of the call, and any repetitive patterns can provide valuable clues. The location from which the sound originates, such as from a tree, rooftop, or from a bird flying overhead, also helps narrow down possibilities.
Modern technology offers practical tools for bird sound identification. Smartphone applications such as Merlin Bird ID and BirdNET allow users to record sounds, and the app then attempts to identify the species in real time. These apps often utilize artificial intelligence to recognize bird vocalizations. Online bird call databases, like those provided by the Cornell Lab of Ornithology’s Macaulay Library or Xeno-canto, offer extensive libraries of bird sounds for comparison. Patience and attentive listening are beneficial when trying to pinpoint the source of a mysterious nocturnal screech.