The Great Horned Owl is known for its wide repertoire of vocalizations. This large owl uses different calls and sounds to communicate with other owls and to establish its territory. Great Horned Owls have a complex vocal communication system that includes a variety of hoots, screams, barks, hisses, and other sounds.
Hooting
The most recognizable vocalization of the Great Horned Owl is its deep, resonant hooting. This territorial call carries for miles and is used by these owls to establish and defend their nesting territories. The male’s hoot is lower-pitched than the female’s. Great Horned Owls have a wide range of hoots they use. Some differences in hoots may signal information to other owls such as alarms, food availability, and more.
Territorial Hoots
Male Great Horned Owls use their deep, booming hoots to establish territories and attract mates. These territorial calls are often made while perched high in a tree. The hoots carry far and wide, communicating the owl’s ownership of a certain area. If an intruding owl hoots within an established owl’s territory, it may be answered with aggressive hoots and even physical conflict.
Contact Hoots
Great Horned Owls use contact hoots to locate other owls and communicate their position. These hoots are often made by paired owls, helping the birds keep track of each other’s location. Contact hoots are shorter and higher-pitched than the male’s territorial hoots.
Food-associated Hoots
When one owl has captured prey, it may emit special food-associated hoots. These calls communicate the presence of food to other owls. The owls at the nest may then return with food for their young. Food-associated hoots have a faster rhythm and more variable pitch than territorial hoots.
Screams and Hisses
In addition to hooting, Great Horned Owls have an assortment of screams, shrieks, and hisses they use to communicate. These alarming and aggressive vocalizations are often used in response to threats or competition.
Alarm Screams
When alarmed or agitated, Great Horned Owls emit a high-pitched, piercing scream. This functions as an alarm call to communicate danger to other owls. It also serves to startle potential predators. The scream may resemble that of a human woman shouting.
Aggressive Screams
These owls also produce aggressive, lower-pitched screams during conflicts over territories or nesting sites. The screams are used to intimidate opponents during challenges and fights.
Distraction Screams
Great Horned Owls may use loud, repetitive shrieking when defending a nest. These distraction screams are intended to scare away potential nest predators. The frantic calls also help divert attention away from the nest containing eggs or owlets.
Hissing
When highly alarmed or aggressive, Great Horned Owls may make a loud hissing or puffing sound, resembling a cat. Owls hiss as a warning when defending nests or when mobbed by other birds. The hiss serves to intimidate threats.
Bill-snapping
Great Horned Owls communicate with a loud bill-snapping sound, used in both aggressive and non-aggressive contexts. This snapping functions as a warning to indicate dominance and establish territories.
Territorial Bill-snapping
Owls snap their bills as a territorial display, often from prominent roosts. The cracking sound carries far, advertising the owl’s claim on an area. Bill-snapping serves as a warning to chase away competitors.
Non-aggressive Bill-snapping
Great Horned Owls also snap bills in non-threatening situations, such as between mated pairs or parents and offspring. This helps maintain connections between birds and may coordinate movements between them.
Barking
The barking vocalization of the Great Horned Owl does not sound like a dog’s bark, but is a low-pitched hooting or guttural sound. This call is used by males when delivering food to females during courtship. Barking seems to communicate the male’s arrival at the nest.
Whines, Coos, and Pips
Great Horned Owls have a repertoire of other sounds used mainly in close-range communication, including whines, coos, and pips. These calls are exchanged especially between parents and offspring.
Whines
Owlets will make soft squeaking or whining sounds when begging for food from parents. Female owls also whine when begging from males before and after mating.
Coos
Adults may make soft cooing sounds to sooth offspring and communicate affection. Cooing seems to help maintain the bond between parents and young.
Pips
High-pitched piping or peeping is often made by young owlets when they are still in the nest. It signals distress and works to draw the attention of parents.
Non-vocal Sounds
In addition to vocalizations, Great Horned Owls communicate with other sounds produced by clapping their wings together or striking surfaces with their talons.
Wing-clapping
Great Horned Owls may clap their wings together to create loud cracking sounds. Like bill-snapping, this functions as an audio warning signal and territorial display. The claps communicate the owl’s location and dominance.
Foot-stamping
Owls stamp their feet to make thumping sounds on the bottoms of nests or other surfaces. This serves as an alarm to warn intruders away. Foot-stamping also seems to function as a territorial display in some cases.
Number of Vocalizations
Researchers have identified at least 10 distinct vocalizations used by Great Horned Owls:
- Territorial hoots
- Contact hoots
- Food-associated hoots
- Alarm screams
- Aggressive screams
- Distraction screams
- Hisses
- Bill-snapping sounds
- Barking sounds
- Whines, coos, and pips
In addition, they make non-vocal sounds like wing-clapping and foot-stamping. The total number of different vocalizations likely falls between 10 and 15 unique sounds. This makes the Great Horned Owl one of the most vocally diverse owl species.
Functions of Vocalizations
Great Horned Owls use their wide repertoire of sounds for these main functions:
- Claiming territory
- Attracting mates
- Communicating locations
- Coordinating parental duties such as feeding
- Begging for food
- Alarming others of threats
- Defending territories and nests
- Maintaining pair bonds
- Soothing young
The many different vocalizations allow Great Horned Owls to communicate distinct messages and behaviors. The vocal complexity likely helps these territorial birds successfully breed and flourish across their widespread range.
Seasonal Variation in Vocalizations
Great Horned Owls exhibit seasonal shifts in their vocal behavior throughout the year tied to breeding cycles:
- Late fall to early winter is peak calling season. Males hoot persistently to claim territories and attract females.
- Paired birds increase contact calls to maintain bonds through winter.
- Food-begging calls are common in late winter and early nesting season as males provision females.
- Territorial calls decrease during incubation but increase again after hatching.
- Alarm and agitation calls peak in late nesting season while defending young.
- Vocalizations are reduced in late summer during molting period.
The seasonal shifts in vocal behavior relate to the owl’s changing reproductive needs throughout the year. More research is still needed to fully understand Great Horned Owl vocal communication and how it varies across different regions and habitats.
Regional Dialects
There is some evidence that regional “dialects” may exist in Great Horned Owl vocalizations across different areas. Factors like habitat, elevation, climate, and genetics may shape local nuances in dialect:
- Pitch and cadence of hoots may differ subtly between regions.
- Southern owls may start hooting earlier in evening than northern owls.
- Amount of variation in hoots may differ between habitats.
- High-elevation owls have lower-pitched, slower hoots than lowland owls.
However, more research is needed to conclusively demonstrate and measure potential regional dialects in Great Horned Owls. Vocalizations likely follow local trends while allowing communication across the species’ full range.
Use of Sound Archives
Scientists are able to study details of Great Horned Owl vocalizations by accessing audio recordings from sound archives. These archives collect high-quality recordings from across the owls’ range. Analysis of recordings helps reveal nuances and variability in sounds:
- Macaulay Library at the Cornell Lab of Ornithology has over 1,500 Great Horned Owl recording.
- xeno-canto has over 500 recordings submitted by field recordists.
- Many state, university, and museum audio collections also exist.
Sound archives allow more systematic study of owl vocalizations. The growing availability of recordings provides insights into the complex vocal repertoire of Great Horned Owls.
Conclusion
Great Horned Owls possess an impressive array of over 10 distinct vocalizations used to communicate different behaviors and messages. Their vocal repertoire includes various hoots, screams, hisses, barks, snaps, and more. These sounds help owls claim territories, attract mates, alarm others of threats, and coordinate breeding activities. Great Horned Owl vocalizations also show seasonal shifts and possible regional dialects. Continued research and audio recordings help provide a detailed picture of the vocal complexity behind this common yet mysterious nocturnal hunter.