How Male Hummingbirds Use Tail Feathers to Create Courtship Sounds

Jul 30

Scientists continue to uncover fascinating details about hummingbird behavior, especially when it comes to their elaborate courtship displays. Male hummingbirds are known for dramatic aerial dives meant to attract females, and these displays often include sharp buzzing or chirping sounds as the bird sweeps through the air.

For many years, researchers debated whether these sounds came from the hummingbird’s voice or from its feathers. A study published in the journal Evolution explored this question and revealed something remarkable: in several hummingbird species, the sounds produced during courtship displays are created by specialized tail feathers vibrating in the air.

For anyone who has watched hummingbirds perform display dives in the wild, this research helps explain one of the most exciting parts of their behavior.

The Mystery of Hummingbird Display Sounds

Male hummingbirds perform elaborate aerial displays during the breeding season. These displays typically involve:

climbing high into the air
diving steeply toward a female
producing a buzzing or chirping sound at high speed

For decades, scientists wondered how these sounds were produced. While hummingbirds do make vocal sounds, the noises heard during dive displays often occur when the bird is moving too fast for vocalization to be responsible.

Researchers suspected the sound might be produced by aeroelastic flutter, a phenomenon where air flowing across a feather causes it to vibrate and generate sound.

Studying the Bee Hummingbird Clade

The researchers examined several hummingbird species known for producing sounds during their courtship displays. Many of these species belong to what scientists call the bee hummingbird clade, formally known as the tribe Mellisugini.

This evolutionary group includes some of the smallest hummingbirds in the world, including the famous Bee Hummingbird (Mellisuga helenae), which is the smallest bird on Earth. Species within this clade share a number of anatomical traits and display behaviors that make them especially interesting for studying hummingbird evolution.

By comparing species within this group, scientists were able to investigate how specialized tail feathers may have evolved to produce sound during courtship dives.

Investigating the Role of Tail Feathers

To better understand how these sounds are produced, researchers examined the shape and structure of hummingbird tail feathers and studied how air flows across them during flight.

The scientists analyzed:

feather shape and curvature
feather stiffness
airflow patterns around the tail during dives

They also conducted experiments using isolated feathers placed in controlled airflow conditions to observe how the feathers vibrated.

The results confirmed that certain tail feathers are uniquely structured in ways that allow them to vibrate and produce sound when air flows rapidly across them.

Specialized Feathers Designed for Sound

The study revealed that some hummingbird species have evolved highly specialized tail feathers that function almost like tiny musical instruments.

These feathers have characteristics that allow them to vibrate at particular frequencies, including:

curved feather shafts
narrowed feather tips
increased stiffness in specific areas

When air rushes past these feathers during a high-speed dive, the feathers flutter rapidly and produce the distinctive sounds heard during the display.

Different hummingbird species produce different sounds because their tail feathers have evolved slightly different shapes and structures.

Evolution Driven by Courtship

The research suggests these sound-producing feathers likely evolved through sexual selection.

In many bird species, males perform elaborate displays to attract females. Over time, females may begin to prefer certain sounds or display characteristics, which influences how these traits evolve.

In hummingbirds, this process may have led to the development of specialized feathers capable of producing louder or more distinctive sounds during courtship dives.

The buzzing or chirping sound heard during a hummingbird’s dive may therefore serve as an important signal that helps females evaluate potential mates.

A Hidden Musical Instrument

One of the most fascinating aspects of this research is the idea that hummingbird feathers function almost like tiny musical instruments.

Rather than relying solely on vocal calls, these birds can use airflow across their feathers to produce sound during flight.

When the conditions are right, the feathers vibrate in a way that creates a clear acoustic signal, adding another dimension to the hummingbird’s already impressive courtship display.

A New Perspective on Hummingbird Displays

For birdwatchers and photographers, hummingbird courtship dives are already among the most exciting behaviors to observe. This research adds a deeper layer of understanding by revealing the aerodynamic and evolutionary mechanisms behind those brief but dramatic aerial performances.

The sound of a hummingbird dive is not simply an incidental noise. It is part of a carefully evolved display that combines flight, feather structure, and aerodynamics.

Studies like this continue to show that even familiar birds still have many secrets waiting to be discovered.

Research Credit

This article summarizes findings from the following scientific study:

Christopher J. Clark, Jimmy A. McGuire, Elisa Bonaccorso, Jacob S. Berv, and Richard O. Prum (2018).
Complex coevolution of wing, tail, and vocal sounds of courting male bee hummingbirds
Evolution.

Read the Original Paper

Readers interested in the full methodology, experiments, and analysis can consult the original publication.

Frequently Asked Questions

Scientific studies often raise new questions about how hummingbirds communicate and perform courtship displays. Here are some common questions readers may have after learning about how hummingbird feathers produce sound during aerial dives.

Yes. In several hummingbird species, specialized tail feathers vibrate during high-speed dives, producing audible buzzing or chirping sounds.
Male hummingbirds perform these aerial displays during the breeding season to attract females.
In many species, the sounds are produced by vibrating feathers rather than vocal calls.
The bee hummingbird clade refers to a group of closely related hummingbirds within the tribe Mellisugini, which includes the Bee Hummingbird and several other small species.
Understanding how hummingbirds produce these sounds helps scientists learn more about courtship behavior, feather evolution, and how sexual selection shapes bird anatomy.