Hummingbirds are a family of small, brightly colored birds found only in the Americas. They are known for their ability to hover in mid-air and fly backwards as well as their namesake behavior of “humming” their wings rapidly while feeding on nectar. But despite their name, hummingbirds do not actually produce any humming or buzzing sound with their vocal cords – so why are they called “hummingbirds”?
The sound of their wings
The most likely explanation has to do with the sound created by their rapidly beating wings. Hummingbirds can flap their wings up to 80 times per second, creating a persistent humming, buzzing or whirring noise as they fly. This distinct resonant sound is caused by the aerodynamics of their specialized wing structure and flight style. So while they don’t vocalize a hum, the characteristic noise produced by their wings in motion gives the impression of a constant hum or buzz.
Wing anatomy
Hummingbirds have uniquely structured wings that allow them to hover and maneuver swiftly. Their wings are relatively short and stiff compared to other birds, with long hand bones and short arm bones. The wings are optimized to enable hovering, with symmetrical primary feathers on both the top and bottom surfaces. As the wings beat at high frequencies, the airflow over the specially angled feathers produces lift while minimizing drag and turbulence. This keeps their bodies aloft while permitting precise steering in any direction.
Fast wingbeats
The wings of hummingbirds beat rapidly – ranging from 12 beats per second up to an incredible 80 beats per second during courtship displays. This allows them to generate enough lift to hover in place as they feed on flower nectar. The actual rate depends on the size of the hummingbird species – the smaller the bird, the faster its metabolism and typical wingbeat frequency. For comparison, most other birds only flap their wings 3 to 10 times per second.
Hummingbird Species | Wingbeat Frequency (beats/second) |
---|---|
Ruby-throated Hummingbird | 53 |
Rufous Hummingbird | 55 |
Calliope Hummingbird | 75 |
Anna’s Hummingbird | 12 |
As the chart shows, wingbeat frequency varies significantly between different hummingbird species. The smallest species, like the Calliope Hummingbird, can beat their wings up to 75 times per second, contributing to the characteristic buzzing hum.
Early descriptions of hummingbirds
The unusual sound produced by hummingbirds’ rapidly beating wings was likely a key factor in their naming by early European explorers and naturalists who documented the species for the first time in the Americas. Descriptions highlight the audible “humming” or “murmuring” sound made by their wings as they hovered near flowers.
For example, one early account from an English explorer in Guiana in 1596 described them as “one sort of small birds, some call them hummingbirds, because they say their humming noise as they flie.” Here the name clearly links to the humming sound created by their wings.
Mark Catesby’s account
In his Natural History from the 1740s documenting the flora and fauna of the Americas, Mark Catesby wrote:
“The Humming Bird is one of the smallest Birds yet known, not much exceeding the size of a large Humble-bee…they make a continual murmuring noise like a spinning wheel, from whence I gave them the name of Humming Bird.”
Again this account highlights the “murmuring noise” resembling a spinning wheel that gave rise to Catesby terming them “Humming Bird.” The humming sound produced by their wings in flight was enough to earn them this distinctive name.
Comte de Buffon’s description
The influential French naturalist Comte de Buffon also emphasized the sound in his description:
“Some of these small birds emit a continually repeated shrill and murmuring sound…it is from this particular murmur that the Spaniards call them zummingueros, and the French oiseaux-mouches, or humming-birds.”
De Buffon’s account again links the name “hummingbirds” to the humming noise they generate with their fast-beating wings as they hovered near flowers.
No true vocal humming
While their wings produce a humming sound as they fly, hummingbirds do not actually use their voice to hum or make music. They produce vocalizations for communication like other birds, using chirps, squeaks and chatters to defend territory, attract mates, or signal alarm. However, they do not sing or create tuneful humming with their vocal cords.
When sitting on a perch, hummingbirds are nearly silent. Only when taking flight do their wings start beating rapidly enough to create the characteristic hum. So the name “hummingbird” is not derived from any vocalization ability – it purely originates from the audible buzz of air forced over their wings as they fly.
Vocalizations
The main vocalizations hummingbirds produce with their syrinx (vocal organ) include:
- High-pitched squeaks or chip notes used to defend territory
- Shrill alarm calls when defending resources or young
- Mechanical buzzes and chatters during courtship rituals
- Begging calls by nestlings to summon their mothers
These vocal sounds are used for communication but do not produce tuneful hums or melodies. Only their aerodynamically optimized wings create the humming noise that gives them their name.
Non-vocal sound production
Male hummingbirds also use non-vocal means to create sounds for courtship displays. Some species can produce mechanical sounds by shuffling or snapping their tail feathers. Others extrude their tail feathers and flutter them rapidly against the air to make twittering or buzzing noises. These non-vocal sounds are used to attract females but again do not involve true humming or melodic vocalizations.
Significance of the humming sound
The humming noise generated by hummingbirds serves an important evolutionary function beyond earning them their evocative name.
Researchers have found the resonant humming sound created by wing beats acts as a reinforcement signal. When feeding on nectar, hummingbirds cannot rely much on vision to stabilize their position. However, they can hear the pitch and volume of the humming sound their wings make. This provides auditory feedback about their position relative to the flower, helping them make adjustments and maintain hover stability.
By allowing precise hovering control, the humming sound enables more efficient feeding. This helped drive the evolution of specialized wing anatomy and very fast wingbeats that maximize this auditory feedback effect.
Hover stability
Studies monitoring wing sounds using laser vibrometry confirm hummingbirds actively control the frequency and amplitude of the humming generated by their wings. As they initiate a hover, they tune their wingbeats to produce just the right volume and pitch of hum at around the 100 Hz frequency. This serves as an acoustic reference enabling them to actively stabilize their position using auditory feedback from the hum.
Feeding efficiency
Being able to maintain a stable hover via auditory cues from the wing hum lets hummingbirds precisely orient themselves relative to flowers. This is especially helpful when accessing nectar from curved or otherwise complex flower shapes. By keeping position with minimal visual guidance, hummingbirds can feed more efficiently.
Research on hummingbird behavior and neurobiology reveals specialized neural connections between auditory regions of their brain and vocal motor centers. This integration supports their ability to constantly adjust wing angles and use the resulting pitch changes in the hum for positional stability.
Conclusion
In summary, hummingbirds get their descriptive name not from vocal humming, but from the characteristic humming, buzzing or whirring sound produced by their rapidly beating wings during flight. Early European explorers named them after the conspicuous humming noise they produced when hovering near flowers.
While they do not vocalize melodic hums, the sound of their wings serves an important biological function by providing positional feedback through pitch changes. This enables stable hovering and efficient feeding. So their name ultimately derives from an auditory impression matching their signature behavior in flight – even if they don’t actually hum!