Great horned owls are one of the most widespread owl species in North America. They are large, powerful owls that can exert over 300 pounds of force with their talons. A common question asked about great horned owls is whether they can fly silently. The answer is that great horned owls can fly very quietly, but they do make some noise when flying. There are several key factors that allow great horned owls to fly with minimal sound:
Soft, fluffy plumage
Great horned owls have incredibly soft, fluffy plumage that muffles the sound of air passing over their wings during flight. The leading edges of their primary flight feathers have a soft, fringed appearance. This downy surface area diffuses turbulence and reduces noise. Most other owl species share this adaptation as well. The sound-dampening plumage allows great horned owls to fly and hunt with stealth.
Large wings
The wings of great horned owls are quite large relative to their body size. The large wing area helps generate lift and thrust with fewer wingbeats per minute compared to smaller birds. The lower flapping rate and slower wing speed produce less noise. Great horned owls only need to flap their wings occasionally to stay aloft or maneuver. They take advantage of wind conditions and thermal columns to soar silently for long periods.
Specialized feather edges
Owls have leading feather edges with specialized fringes and comb-like serrations that help reduce turbulence and sound. When air flows over the trailing edge of an owl’s wing, the comb-like fringes on the leading edge help smooth the passage of air, reducing noise. This silencing effect gets amplified across the owl’s entire wing. Great horned owls and most owl species possess these specialized feather adaptations for quiet flight.
Soft forward-facing body feathers
The body feathers of great horned owls are soft, dense, and point forward. This design creates a smooth surface and eliminates any gaps between feathers where noise-generating turbulence could occur. The sleek frontal profile of the feathers minimizes interference as the owl flies through the air. The tail feathers are also relatively short and rounded compared to other raptors, further reducing turbulence.
How Quietly Can Great Horned Owls Fly?
Great horned owls are capable of flying extremely quietly thanks to their specialized adaptations. In fact, the noise great horned owls produce while slowly flying is comparable to ambient noise levels:
| Sound Source | Decibel Level (dB) |
|---|---|
| Great horned owl in flight | 10-15 dB |
| Leaves rustling | 10-20 dB |
| Whispering | 15-30 dB |
As the table shows, a great horned owl flapping slowly and steadily to cruise along generates only 10-15 decibels of noise. For reference, the quietest sounds humans can hear measure just above 0 dB. Normal conversation is about 60 dB. The near-silent flight of great horned owls is a key hunting adaptation that allows them to sneak up on prey without detection.
Stealth Mode
When flying slowly while hunting or gliding down to capture prey, great horned owls are essentially silent to human ears. The noise level of an owl in stealth flight mode approaches the quietest threshold of human hearing. Their ability to fly in virtual silence gives great horned owls an important predatory edge. Prey species like rabbits, squirrels, and mice cannot hear the owl approaching.
Hearing Sensitive Prey
Many common great horned owl prey species have extremely sensitive hearing adapted for predator detection. Rabbits and hares can rotate their large outer ears to precisely locate sounds. Mice and squirrels also have excellent high frequency hearing. But the muted flight of a great horned owl usually falls below the audible detection range of prey species. Only at very close range might prey hear the owl.
Masking Noise
Ambient noise from rustling leaves, running water, or other natural sounds in the environment can further mask any slight sound great horned owls make in flight. On windy nights, the noise generated by air currents through vegetation covers any minimal sounds from the owl’s wings. Great horned owls utilize natural audio camouflage to get even closer to prey undetected.
Great Horned Owl Flight Speeds and Noise
While great horned owls are capable of near-silent flight, the amount of noise they generate is dependent on flight speed and wing-flapping rate. Some general noise levels at different flight speeds:
| Flight Condition | Speed (mph) | Sound Level (dB) |
|---|---|---|
| Cruising/gliding | 10-20 | 10-15 |
| Slow flapping flight | 15-25 | 15-30 |
| Moderate speed flapping | 20-35 | 30-45 |
| Fast wingbeats | 30-40 | 40-60 |
As the table shows, great horned owls are near-silent when cruising, gliding, or flying slowly. As they accelerate and flap their wings faster to fly at higher speeds, the noise increases. During a high-speed aerial pursuit of prey, the noise level can rise to 60dB, comparable to a normal human conversation. Only during take-off might an owl briefly reach noise levels of 80dB or more. But while hunting and maneuvering, great horned owls minimize sound through slow, controlled flight. Their stealth allows them to strike prey by surprise.
Great Horned Owl Wing Structures That Reduce Sound
In addition to the soft plumage that dampens turbulence, great horned owls have specialized wing structures that help minimize noise generation:
Leading Edge Fringe and Serrations
The leading edges of great horned owl primary wing feathers have flexible fringe endings and microscopic serrations. These structures diffuse and smooth out airflow over the wing surface to eliminate noise-creating turbulence. Other owl species have similar wing edge specializations to eliminate sound.
Trailing Edge Fringe
The rear trailing edges of great horned owl wing feathers also have flexible fringe structures that muffle turbulence and prevent fluttering that could generate sound. The trailing edge fringe creates a seamless, quiet transition as air passes off the back end of the wing.
Downy Upperside Surface
The feather barbules on the upper side of great horned owl wings are covered in fine downy structures. This soft upper surface prevents airflow disruption and noise generation. The downy coat gives great horned owl wings a velvety silent quality when seen in flight.
Leading Primary Feathers
Great horned owls have 10 large primary flight feathers on the leading edge of each wing. These primaries have the finest fringe and specialized adaptations for eliminating noise. The primaries do most of the work to provide lift and thrust with minimal sound.
Broad Wingspan
With wing spans approaching 5 feet, great horned owls have a large surface area that generates ample lift with less flapping. Their broad wings allow these large owls to fly slowly and smoothly with no wasted motion.
How Do Great Horned Owls Locate Prey Without Sound Cues?
Since great horned owls make almost no sound when flying slowly, they cannot rely on auditory cues to hunt prey. Instead, great horned owls utilize these tactics:
Exceptional Low Light Vision
Great horned owls have some of the best night vision of any animal on earth. Their massive eyes can detect subtle movements in extremely low light. Excellent night vision allows great horned owls to spot and track prey visually from far distances even in pitch darkness.
Binocular Vision
Great horned owls, like most owl species, have forward-facing eyes that provide detailed binocular vision. By overlapping visual fields from each eye, great horned owls gain accurate depth perception and distance judgment, critical for precision hunting. Their binocular vision also enables detection of faint motion.
Keen Hearing
When perched or at rest, great horned owls can detect prey rustling and moving through auditory cues. Their asymmetrical ear openings provide enhanced directional hearing to pinpoint sound sources. Once prey is heard, great horned owls can silently glide in for the kill.
Element of Surprise
By combining exceptional low light vision, binocular vision, and keen hearing, great horned owls can surprise prey from unexpected angles. Even when prey hears the owl’s approach at the last second, it is too late to react or escape. The owl’s stealth gives them an advantage.
How Do Great Horned Owls Hunt Using Silent Flight?
Great horned owls utilize specialized silent flight techniques to hunt prey effectively:
Searching Glides
Great horned owls will silently glide 30-60 feet above the ground while scanning for prey with eyes and ears. These searching glides allow great horned owls to cover large hunting territories efficiently without alarming prey.
Circling Flights
Great horned owls sometimes circle high above potential hunting areas while watching and listening for prey activity below. The wide circling flights utilize air currents and thermals for effortless silent soaring.
Patient Perching
Owls will perch inconspicuously on branches, poles, or other high vantage points and wait patiently for sights or sounds of prey. Their camouflage plumage helps great horned owls blend in while perched.
Stealthy Approaches
Once prey is sighted, great horned owls are masters of flying slowly and smoothly into range without generating noise. They approach from angles where vegetation, terrain, or shadows can conceal their advance.
Swift Silent Strikes
With prey positioned below them, great horned owls drop or dive quickly and talon prey before it knows what happened. At close range, great horned owls reach speeds over 150 mph executing these lightning-fast ambush strikes.
Surprise Takeoffs
Great horned owls sometimes take surprised prey by first walking stealthily on foot near cover. Then with explosive force, they launch airborne and pounce, giving prey no time to react.
How Do Great Horned Owls Care For Their Young?
Great horned owls do not use their silent flight capabilities while caring for offspring in nests. Instead, they utilize other tactics:
Nest Site Selection
Great horned owls choose secluded, sheltered nest sites high up in trees, cliffs, or abandoned structures. Isolated dense sites help conceal owls and their young from predators and weather.
Defensive Aggression
Adult great horned owls become very aggressive near their nests. They may make loud vocalizations and even attack potential threats that approach too closely. This helps deter predation.
Constant Care
For the first few weeks after hatching, great horned owl young require almost constant care and feeding by parents. Parents continually hunt to provide enough food to sustain the rapidly growing owlets.
Protection and Shade
On hot days, adult great horned owls shade the young by positioning themselves between nests and the sun. They may also flutter wings to cool the nest interior. Cold nights may require adult owls to brood young closely.
Frequent Feedings
Young great horned owls have voracious appetites and grow rapidly. Parents make frequent feedings, sometimes hunting almost continuously to satisfy the owlets. Around 5-6 weeks, the young reach adult size.
Fledging Flight Practice
As wings develop, great horned owlet young will flap wings in the nest and climb onto branches. Short practice flights help build flight muscles and skills. Parents monitor first flights closely for safety.
Conclusion
Great horned owls possess a remarkable ability to fly with minimal sound due to specialized plumage and wing structures that eliminate turbulence and noise. While not completely silent, great horned owls can reach noise levels on par with ambient nature sounds when flying slowly. This acoustic stealth gives great horned owls a huge advantage locating and ambushing prey in darkness. Vision and hearing adaptations allow them to hunt prey successfully without relying on sound cues. Through masterful silent flight capabilities and stealthy hunting behaviors, great horned owls thrive as powerful nocturnal predators across North America.
