There are several owl species that are known for making whistling or whistling-like vocalizations. The most common owls that produce whistling calls are the following:
- Eastern Screech Owl
- Western Screech Owl
- Great Horned Owl
- Northern Saw-whet Owl
- Barn Owl
Whistling vocalizations serve different purposes depending on the owl species. Screech owls and saw-whet owls use whistles to communicate with mates and defend territories. Great horned owls whistle to signal warnings or declare territory ownership. Barn owls create eerie screeching whistles when hunting.
The frequency, pitch, tone and repetition of the whistles can indicate the age, sex, species and intent of the owl. Learning to distinguish owl whistles takes practice but can help birders identify these nocturnal birds, even when they remain hidden.
Eastern Screech Owl
The Eastern Screech Owl (Megascops asio) gets its name from its familiar whistling song. This medium-sized owl has ear tufts, brightly-colored eyes and dappled brown and grey plumage that provides excellent camouflage.
Eastern Screech Owls use a series of whistles to communicate their location and defend territories. The whistles are created by air rushing over traditional owl hoots. The song consists of a long whistle followed by a trill that drops in pitch.
Both male and female Eastern Screech Owls sing but the pitch differs. Males produce low-pitched whistles with a humming hoarseness. Females use higher-pitched, clearer whistles. The frequency of singing increases during breeding season as pairs duet to strengthen bonds and announce territory.
Eastern Screech Owls can produce a rattling screech when alarmed but the typical song is a bouyant whistle. This nocturnal bird hunts from perches in wooded areas and nests in tree cavities. Its small size, camouflage and whistling allow the Eastern Screech Owl to remain well-hidden.
Western Screech Owl
Similar to its eastern cousin, the Western Screech Owl (Megascops kennicottii) is named for its whistling song. This compact owl inhabits wooded areas west of the Rocky Mountains.
Western Screech Owls whistle to declare territory ownership and communicate with mates. Whistling increases during the spring breeding season. Males produce a low-pitched hooting whistle: “hooo-hoo-hoo-hoooooo.” The song has a descending tone with a trill at the end.
Females respond with a higher-pitched whistle that is more shrill and urgent sounding. The male-female duets strengthen pair bonds while warning rival owls away. Although less common, Western Screech Owls can produce a rattling shriek when alarmed.
In addition to whistling, Western Screech Owls may clatter their beaks or produce a chuckling song. But the most recognizable vocalization is the melancholy descending whistle that gives this species its name.
Great Horned Owl
The deep hooting calls of the Great Horned Owl (Bubo virginianus) are instantly identifiable. But Great Horned Owls also mix in whistling calls, particularly during territory disputes.
This large, powerful owl uses low-pitched hoots to declare territory ownership. If an intruding Great Horned Owl encroaches on a territory, the resident will respond with aggressive whistling. This whistling signals a warning to the trespasser.
Great Horned Owls produce a shortened version of their typical five-hoot sequence when whistling. It may sound like “Who-who-whooooo” with an airy whistling quality. The whistles are deeper in pitch than the calls of screech owls.
Whistling indicates strong territory ownership and the willingness to fight intruders if necessary. But Great Horned Owls may also whistle simply to communicate their presence to mates and signal occupancy of the area.
Northern Saw-whet Owl
The Northern Saw-whet Owl (Aegolius acadicus) is a small forest owl named for its repetitive, whistling call. Saw-whet refers to the sound the owl’s song resembles.
Northern Saw-whet Owls produce a short, whistled toot that rises slightly in pitch before dropping off. It is often described as sounding like “too-too-too.” The typical song is a series of whistles repeated steadily every few seconds.
Saw-whet Owls whistle this monotonous song to mark territory boundaries and attract mates. Whistling increases during courtship in late winter and early spring. Males may sing almost continuously through the night.
The Northern Saw-whet Owl’s whistling call carries surprisingly far for the owl’s small size. Birders rely on detecting this repetitive whistling to identify this secretive species. Saw-whet Owls nest in tree cavities and hunt from low perches within dense forests across North America.
Barn Owl
Perhaps the most iconic of the whistling owls is the Barn Owl (Tyto alba). This owl produces eerie, raspy screeching and whispering calls while hunting at night. The screeches have a whistling, jittery quality.
Barn Owls don’t hoot like most other owls. Instead, they vocalize with a long, shrill shriek that fluctuates and trails off. This high-pitched scream starts with a piercing whistle and ends with a wavery fading hiss.
The unearthly vocalizations likely help Barn Owls locate prey in darkness. The sounds may startle and confuse small animals, causing them to reveal their location. Barn Owls feed almost exclusively on small rodents.
While hunting, Barn Owls screech about once per minute. The wailing whistles carry surprisingly far and inspire scary legends. But the spectral sounds are simply the Barn Owl’s secret weapon for nocturnal hunting success.
Whistling Traits Based on Species
Owl Species | Whistling Description |
---|---|
Eastern Screech Owl | Whistled song used for territory defense; long whistle leading into bouncing trill; male pitch lower than female |
Western Screech Owl | Territorial and pair bonding whistle; males produce low-pitched hooting whistle; female response higher-pitched |
Great Horned Owl | Low, abbreviated hoots with airy whistling quality; signals warnings to intruders |
Northern Saw-whet Owl | Short, whistled “too-too-too” call; used to mark territory and attract mates |
Barn Owl | Eerie, raspy screeching whistles; likely used to locate prey while hunting |
Whistling Purpose Based on Species
Owl Species | Purpose of Whistling |
---|---|
Eastern Screech Owl | Territory defense; pair bonding |
Western Screech Owl | Territory defense; pair bonding |
Great Horned Owl | Territorial warnings |
Northern Saw-whet Owl | Attract mates; mark territory |
Barn Owl | Hunting |
Identifying Owls by Whistling Calls
The whistles, screeches and toots of owls at night reveal their presence in an area, even when the birds remain unseen. With practice, birders can learn to identify common owl species by sound alone. Here are some tips:
- Listen for repetition – A repeated series of whistles likely signals a saw-whet owl
- Note changes in pitch – A dropping pitch indicates an Eastern or Western screech owl
- Distinguish low vs. high tones – Lower whistles signal a male screech owl, higher tones a female
- Listen for duets – Whistling exchanges mean paired screech owls are bonding
- Consider the habitat – Barn owls whistle over open fields while saw-whets call from dense forest
- Detect hoarseness or raspiness – A raspy screech reveals a barn owl
Owl whistles may be brief or last many seconds. Paying attention to the nuances and patterns can help identify which species is calling before it drifts silently away into the darkness.
Mimicking Owl Whistles
Because owl whistles play an important role in communication and hunting, birders and researchers sometimes attempt to imitate these sounds to draw owls in or elicit a response.
Certain owl species like saw-whets and screech owls are highly territorial. Mimicking the whistling call of one of these species may cause the resident owl to fly closer to investigate and defend its territory. This can allow birders to spot hard-to-find owls.
Researchers may also imitate owl whistles when conducting species surveys. By reproducing the sound, they hope to trigger a response whistle that confirms the owl’s presence and location. This is less disruptive than broadcasting a recording.
Attempting to mimic owl whistles takes practice. Each species has a unique tone, pitch, volume and cadence. It’s important to listen carefully and fine-tune your imitation whistle to avoid confusing owls with inaccurate calls. With time and effort, you may be able to perfect whistles that bring these mysterious birds in for a closer look.
Conclusion
The whistles and screeches of owls at night reveal that these elusive raptors are present and active, even when they remain out of sight. Eastern and Western Screech Owls trill and toot to defend territories and find mates. Great Horned Owls mix aggressive whistles into their deep hooting. Northern Saw-whet Owls repeat a simple, whistled phrase. Barn Owls shriek hunting calls that waver and trail off eerily.
Each owl species has a signature style of whistling that serves a distinct purpose. By tuning into the unique nuances of each call, birders can identify the owls based on vocalizations alone. With practice, you too can learn to recognize the owl species behind those haunting whistles in the dark.