A barn owl drifts low over a dark meadow. A vole in the grass below, listening hard for danger, hears nothing at all until the owl’s talons close around it.
Owls fly almost silently because of four features working together: large, light wings that let them fly slowly, a comb of stiff serrations on the front edge of the wing, soft fringes on the back edge, and a velvety upper surface. Together these cut the swishing noise that air makes as it flows over and off a wing.
Key takeaways
- Slow flight is quiet flight: owls have big wings for their weight, so they can glide slowly, which makes less noise (Wagner et al. 2017).
- Three feather tricks: leading-edge serrations, trailing-edge fringes and a velvet-like surface, first described together by R. R. Graham in 1934.
- Measurably quieter: in tests, owl wings were several decibels quieter than the wings of other birds, mostly at higher pitches.
Why are owl wings so quiet?
Most of the noise a bird makes in flight comes from turbulent, swirling air at the edges of its wings. Owls tackle that noise in two ways. Their large, lightly loaded wings let them fly slowly, and slower air makes less noise. Special feather structures then smooth or break up the airflow at the front, top and back of each wing, say Hermann Wagner and colleagues in a 2017 review in Interface Focus.
1. Big, light wings for slow flight
“Wing loading” is how much weight each square metre of wing has to carry. The barn owl’s wing loading is about 33 newtons per square metre, and the review describes its wing as “optimized for low flight velocities.” Across 15 North American owl species, wing loading ranged from 19 to 60 N/m². Barn owls fly at an estimated 2.5 to 7 m/s, roughly 9 to 25 km/h (6 to 16 mph), about the speed of a person jogging or cycling gently.
2. The leading-edge comb
On the front edge of the outermost flight feather, the tips of the barbs stand free, forming a comb of tiny serrations. They are more developed in night-hunting owls than in day-active ones. In wind-tunnel studies reviewed by Wagner and colleagues, serrations cut noise mainly at lower and middle frequencies, though results vary and how big the effect is remains debated.
3. The velvety surface
The top of an owl’s wing feels like velvet because the ends of the barbules are stretched into long, soft extensions called pennula. Experiments with artificial velvet showed it helps keep air flowing smoothly over the wing at low speeds, which may let owls fly even more slowly and quietly.
4. The soft trailing-edge fringe
On the back edge of the wing, the feathers end in a soft fringe 1 to 4.5 mm long. Air leaving a hard, sharp edge creates noise. Theoretical estimates for owl-like fringes suggest a large noise cut at gliding speeds, and engineering tests on modified trailing edges found reductions of up to about 10 decibels (Wagner et al. 2017).
Picture it: an owl wing vs a pigeon-style wing
Run your finger along a feather from a pigeon or gull. The edge is firm and the surface is smooth and slick. On an owl’s flight feather, the front edge is like a tiny comb, the surface feels like a velvet cushion, and the back edge is soft and frayed, like the end of a well-used paintbrush.
Barn owl flight speed (estimate): 9–25 km/h
Source: Wagner et al. 2017 (2.5–7 m/s). Bar shows the range from slow to fast, drawn to scale up to 25 km/h.
How much quieter is an owl than other birds?
In tests reviewed by Wagner and colleagues, owl wings were consistently quieter, especially at higher pitches. One study found barn owl flight noise about 4 decibels lower than the other birds tested at frequencies above 1.6 kHz. Another found an eagle-owl about 5 to 10 decibels quieter than a common buzzard above 400 Hz. Every 10 decibels is a tenfold drop in sound energy.
An older study of tawny owls (Neuhaus and colleagues, 1973) found that most of their flight noise was low-pitched, between 200 and 1,500 Hz. Removing the leading-edge comb did not change the noise in flapping flight, but did make the owl louder just before landing. That suggests the comb matters most at the moment of attack.
Why does silent flight matter to an owl?
Many owls hunt at night and find prey partly by sound. Wagner and colleagues note that owls have a highly developed hearing system with a very low hearing threshold. Silent flight helps in two ways: prey is less likely to hear the owl coming, and the owl’s own wing noise doesn’t drown out the rustle of a mouse in the grass. Scientists still debate which of these matters more.
This makes owls important rodent hunters in many ecosystems. See whether owls eat rabbits for more on what they catch.
Surprising extra: owl wings are inspiring quieter machines
Back in 1934, R. R. Graham studied owl feathers and argued that “It would, therefore, be a mistake to ignore birds as a guide to possible future developments,” as quoted by Wagner and colleagues. Engineers today still test owl-inspired serrations, porous trailing edges and soft coatings on aerofoils to make fans, wind turbines and aircraft quieter.
Myth vs fact
Myth: Owls are completely silent when they fly.
Fact: Owls are much quieter than most birds, but not silent. Measurements show they still make sound, mostly at low pitches, between about 200 and 1,500 Hz in tawny owls (Neuhaus et al. 1973, reviewed in Wagner et al. 2017). Why people believe it: to human ears, a gliding owl often makes no sound we can notice.
Test yourself
1. Name the three feather features that make owl flight quiet.
The leading-edge comb (serrations), the velvety upper surface and the soft trailing-edge fringe.
2. Why does slow flight help owls stay quiet?
Slower airflow over the wings makes less noise, and big, light wings let owls fly slowly.
3. Who first described all three quiet-flight features together?
R. R. Graham, in 1934.
Related questions
Do all owls fly silently?
Not equally. Wagner and colleagues report that leading-edge serrations are more developed in nocturnal owls than in species that hunt by day. Owls that hunt mainly by night and by sound tend to have the strongest quiet-flight features.
Can owls be heard at all when they fly?
Sometimes, especially when they flap hard or land. Their flight noise is low-pitched and quiet. Calls and hoots, of course, are another matter.
What other birds of prey hunt differently?
Falcons rely on speed rather than stealth. See how to tell hawks, eagles and falcons apart, and how peregrine falcons dive.
Where to next?
⬆️ Go up: explore all our animals🔀 Go sideways: do owls eat rabbits?🔀 Go sideways: which animals hunt hawks
Sources
- Wagner, H., Weger, M., Klaas, M. and Schröder, W. (2017). Features of owl wings that promote silent flight. Interface Focus 7: 20160078. doi:10.1098/rsfs.2016.0078.
- Graham, R. R. (1934). The silent flight of owls. Cited and quoted in Wagner et al. (2017); we did not consult the original.
- Neuhaus et al. (1973), study of tawny owl flight noise. Cited in Wagner et al. (2017); we did not consult the original.
Sources checked 12 October 2026.
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