Owls communicate through a diverse range of vocalizations, but the sound that often startles people is the unnerving, high-pitched screech. This sound is a specific signal that serves multiple functions for these nocturnal birds. Understanding the origin and purpose of the owl’s screech helps to demystify one of the most jarring sounds heard in the dark.
Identifying the Screech: Which Owls Are Making That Noise
The most common source of a true, harsh screech is the Barn Owl, which emits a long, raspy scream that has been described as a bloodcurdling shriek. This sound is a primary vocalization for the Barn Owl, unlike the hoot used by many other species, and it can last for about two seconds. This piercing sound often earns the bird the nickname “screech owl,” even though a separate genus exists with that name.
The Eastern and Western Screech Owls, despite their name, do not typically make this harsh screech. The Eastern Screech Owl instead produces a descending, whistle-like whinny or an extended trill. The Western Screech Owl’s call is a series of hoots that speed up toward the end, resembling a bouncing ball. Young owls from many species, including the Great Horned Owl, also make persistent, harsh screeching or screaming sounds as begging calls when demanding food from their parents.
The Function of the Screech: Communication and Territory
The screech serves as a direct form of communication, particularly in situations involving strong emotions. One primary use of the harsh screech, especially for the Barn Owl, is territorial defense. The loud sound warns potential intruders to stay away, acting as a clear declaration of dominance over an occupied space.
The screech also plays a role in mating and pair-bonding. Male Barn Owls use variations of the high-pitched scream to attract a mate, often reaching a higher pitch during courtship. Females use a variation of the screech as a persistent begging call directed at the male for food delivery. Additionally, the loud screeching heard from young owls serves as a distress signal and a highly locatable call that stimulates parents to deliver prey.
Context and Timing: When Screeches Occur
Since most owls are nocturnal, the majority of screeching and other vocalizations occur after dusk and throughout the night. Screeching is often most frequent during the reproductive season, which typically begins in late winter or early spring.
During this time, territorial disputes are heightened as pairs establish nesting sites, leading to more aggressive screeching to ward off rivals. The calls of young owls are also prevalent in the spring and summer as owlets hatch and fledge, constantly screaming for food delivery. The intensity of the calls generally peaks just before sunset and again before sunrise, coinciding with the times of maximum activity for many owls.
Distinguishing Screeches from Hoots and Calls
The screech is fundamentally different from the familiar hoot in its acoustic properties. The screech is a harsh, high-pitched, prolonged, and irregular sound that conveys urgency, aggression, or distress. In contrast, the hoot, typically associated with species like the Great Horned Owl or Barred Owl, is a deep, rhythmic, and softer sound.
The hoot is a primary long-distance vocalization used for contact and territorial advertisement, carrying a lower frequency that travels well. Other owl sounds, like the Eastern Screech Owl’s descending trill or the Northern Saw-whet Owl’s repetitive toots, are more whistle-like and musical than the piercing shriek of a Barn Owl. Owls also use non-vocal sounds, such as hissing at intruders or snapping their bills together when threatened.