The deep, resonant “who” sound often heard at night is frequently attributed to owls, but identifying the specific species requires understanding the precise acoustics of their calls. Pinpointing the source depends on recognizing the distinct rhythm, pitch, and cadence of the nocturnal caller. The deepest and most recognizable hoot belongs to the largest and most widespread owl species across the Americas.
The Source of the Classic “Who”: The Great Horned Owl
The creature most famously responsible for the classic, low-pitched “who” call is the Great Horned Owl (Bubo virginianus). This large, formidable raptor is one of the continent’s heaviest owls, typically measuring 18 to 24 inches in length with a wingspan up to five feet. Its significant size allows it to produce the deep, carrying sound that travels long distances through wooded areas.
Visually, this owl is identified by prominent feathered tufts, often mistakenly called “horns” or “ears,” which are plumes used for camouflage and display. Its mottled gray, brown, and cinnamon plumage provides excellent concealment against tree bark, and a distinct white patch is visible on the throat. The species exhibits reverse sexual dimorphism, meaning the female is typically larger than the male. This powerful hunter uses silent flight and talons to prey on a wide variety of animals, including other raptors and mammals.
Decoding the Hoot: Rhythm and Cadence
The Great Horned Owl’s hoot is a low, sonorous sound that carries a great distance. The typical pattern is a sequence of four to seven hoots, often transcribed as whoo-hoo-ho-whoo-hooo. This rhythm is characterized by a short pause after the first two or three notes, creating a staggered cadence distinct from other owl species.
The hooting serves a primary function in territorial defense, announcing the owl’s presence to potential rivals. It is also a fundamental part of communication between mated pairs, especially during the breeding season. Males and females frequently engage in duets to reinforce their pair bond. The male’s voice sounds noticeably deeper, while the female’s call is slightly higher in pitch and sometimes includes more hoots.
When and Where to Listen
The Great Horned Owl inhabits a vast range across North and South America, from dense forests to desert canyons and urban parks. Listeners have a high chance of hearing their calls in areas with tall trees for roosting and open spaces for hunting. Since they are strictly nocturnal, the best time to hear their characteristic hooting begins right at dusk and continues until dawn.
The owls are most vocal during the late winter and early spring, which marks the beginning of their courtship and nesting season. Males hoot intensely during this time to establish territories and attract a mate. The absence of heavy foliage in winter allows their deep, low-frequency calls to travel farther, increasing the likelihood of hearing this specific vocalization.
Other Common Owl Calls That May Confuse Listeners
While the Great Horned Owl is the source of the classic “who,” other common species also hoot, leading to frequent misidentification. The Barred Owl (Strix varia) is one such bird, but its call differs notably in pattern and quality. Its famous eight-hoot call is often translated as “Who cooks for you? Who cooks for you all?” and possesses a distinct, almost barking quality that is higher-pitched than the deep resonance of the Great Horned Owl.
The Eastern Screech Owl (Megascops asio) offers an entirely different sound that is not a hoot. This much smaller, robin-sized owl produces two main vocalizations: a tremulous, even-pitched trill and a descending whinny. These sounds are common in suburban and rural areas. Differentiating between species requires paying close attention to the number of notes, the tone, and the musical quality of the call.