Do hummingbirds wings make a sound?

Hummingbirds are some of the smallest and most fascinating birds. Their tiny bodies and incredible flying abilities captivate people. One question that often comes up regarding hummingbirds is whether their wings make a sound as they flap so quickly.

Quick Answer

The quick answer is that yes, hummingbird wings do make sound, but it is typically beyond the range of human hearing. Hummingbirds’ wings can beat up to 80 times per second, creating a high-pitched buzzing noise. However, this noise is at a very high frequency, usually above what humans can detect. Special recording equipment is needed to capture the sounds of hummingbird wings.

How Hummingbird Wings Work

To understand why hummingbird wings make noise, it helps to first understand how their wings work. A hummingbird’s wings are specially designed to enable hovering and sustained forward flight. Here are some key features:

• Their wings are relatively long and narrow, providing large surface area for their body size.
• They can flap their wings in a figure-8 pattern, rather than just up and down. This creates lift on both the downstroke and upstroke.
• They can rotate their wings to optimize airflow as they hover and change direction.
• Their wingbeat frequency is incredibly high, up to 80 times per second. This generates the lift needed to hover.
• The bones in their wings are proportionally short and stiff, providing structural support for high-speed flapping.

These special adaptations give hummingbirds exceptional aerobatic abilities. But the rapid wing motion also inevitably generates noise.

What Causes the Sound

There are a few factors that contribute to the sounds made by hummingbird wings:

• Airflow – The passage of air over and under the wings produces aerodynamic noise. The wings are shaped to maximize lift, but this also increases turbulence that creates sound.
• Vortex shedding – As air flows over the wings, vortices and eddies are created at the trailing edges. The repetitive shedding of these small vortices generates noise.
• Structural vibrations – The rapid flapping can cause vibrations in the wing bones and feathers, adding to the noise.
• Collision noise – There is some noise generated when the wings intersect at the end of each stroke during the figure-8 motion.

The noise from all these mechanisms increases with higher wingbeat frequency. So the faster a hummingbird’s wings beat, the more sound is produced.

Noise Frequency and Detection

The noises made by hummingbird wings are of very high frequency due to their rapid wingbeats. Across different hummingbird species, the fundamental frequencies of wing noise range from 2,000 to 10,000 Hz or more. The smallest hummingbirds have the highest frequencies.

For comparison, most humans can only hear sounds up to about 15,000 to 20,000 Hz when young. This high frequency hearing decreases with age. So while the fundamental hummingbird wing sounds are audible to some, the higher overtones are likely beyond human perception.

Specialized recording equipment with ultrasonic microphones can pick up the full spectrum of sounds made by hummingbird wings. Slow motion video cameras have also captured the nuances of how hummingbird wings move through the air.

Do the Sounds Play a Role?

Researchers are still investigating if the sounds generated by hummingbird wings play any biological role for the birds. Here are some potential functions:

• Communication – The wing sounds could convey information to other hummingbirds. Specific sound patterns may indicate courtship, aggression, or feeding.
• Echo location – It is theorized the wing sounds might help hummingbirds orient themselves while hovering at flowers.
• Prey/predator detection – The noises could help hummingbirds locate small prey insects or be an alert for nearby predators.
• No known function – The sounds may simply be an inadvertent byproduct of wing motion without a specific purpose.

More studies focused on hummingbird wing acoustics are needed to clarify if the sounds serve a meaningful role for hummingbirds.

Wing Sounds of Other Birds

While hummingbirds are the masters of high-speed flapping, other birds also generate wing sounds:

• Insects and bats – Smaller birds like swifts and nighthawks make wing sounds when diving or courting similar to hummingbirds.
• Larger birds – The wings of eagles, vultures, geese, and other big birds can create low-frequency sounds audible to humans.
• Owls – Specialized wing feathers allow owls to fly silently, eliminating noise while hunting.
• Courtship displays – Some birds like snipes and manakins clap or snap their wings to create noises for mating displays.

So birds’ wings can produce incidental sounds, specialized sonic behaviors, or silence depending on the species and situation.

Recording Hummingbird Wing Sounds

Capturing audio of hummingbird wings requires specialized high-speed recording equipment. Key components include:

• Ultrasonic microphones – Standard mics can’t pick up the full spectrum. Ultrasonic models can record up to 100 kHz or higher frequencies.
• High sample rates – Digital recordings need sample rates of 300,000 Hz or more to capture ultrasonic sounds.
• Large memory – High sample rates generate huge audio files, requiring substantial memory.
• Fast processors – Processing and writing massive amounts of ultrasonic data requires powerful computer hardware.

In addition, high-speed cameras are often used in sync with the audio recording to correlate wing position with sound generation.

Here is an example table of equipment used in a 2019 hummingbird wing acoustics study:

Specialized windscreens are also used on the microphones to reduce noise from airflow in outdoor settings when recording free-flying hummingbirds.

Analyzing the Wing Sound Frequencies

Recorded hummingbird wing sounds are analyzed using digital signal processing software. Analysis techniques include:

• Frequency spectra – Shows sound energy across different frequencies using fast Fourier transform algorithms.
• Frequency tracking – Identifies how dominant frequencies change over time.
• Filtering – Removes background noise or isolates specific frequency bands.
• Slow motion analysis – Links sounds to high-speed video shot at 1000+ fps.

This processing reveals the fundamental and overtone frequencies produced at different stages of the wingbeat. The results provide insight into hummingbird flight biomechanics and acoustic characteristics.

Example Audio Spectra

Here is an example set of frequency spectra from a 2019 study analyzing a male Anna’s hummingbird vocalizing during a dive:

This shows the wingbeat sound containing strong overtones related to the fundamental 4 kHz tone. In contrast, the vocalization overtones are not as closely harmonic.

Concluding Thoughts

The tiny wings of hummingbirds can flap faster than our eyes can see. While invisible to us, research reveals these rapid wingbeats do generate sound. Specialized audio equipment and analysis are unlocking the ultrasonic acoustic secrets of hummingbirds in flight. This provides insight into the biomechanics that enable hummingbirds’ unrivaled hovering abilities.

So while you may not hear it standing next to a feeding hummingbird, rest assured its wings are buzzing along at high frequency. Next time you see a hover-capable hummingbird, take a moment to appreciate its perfectly evolved form produces such speed, agility and yes, sound.