The Anna’s hummingbird (Calypte anna) is a small hummingbird found along the Pacific Coast of North America. These tiny birds are known for making a variety of buzzing, squeaking, and chirping sounds.
Hummingbirds like the Anna’s hummingbird have specially adapted syrinxes, which allow them to make sounds not typically heard from other birds. The muscles in the syrinx can oscillate very fast, enabling hummingbirds to emit high-pitched squeaks and buzzing noises.
Anna’s hummingbirds use sounds for communication in a few different contexts. Some sounds are made during courtship displays, others are used to signal alarm or aggression, and some sounds help the birds stay in contact with each other.
Courtship Sounds
During courtship displays, male Anna’s hummingbirds produce high-pitched squeaks and buzzes. These sounds are made as part of aerial courtship displays used to attract females.
One display is called the “dive display.” During this display, a male flies 25-100 feet up in the air and then accelerates on a dive path pointed straight down. At the bottom of this dive, he spreads his tail feathers and makes a loud high-pitched squeal or buzzing noise with his syrinx.
Research has found that these dive noises can reach amplitudes of up to 105 decibels measured from 6 feet away. This equates to the noise level of a loud motorcycle! The sounds are thought to communicate to watching females that the male is fit and strong.
Females also make sounds during courtship rituals. They use a high-pitched squeaking noise to signal interest or rejection of a displaying male. These female sounds provide feedback to the male about whether his display has successfully attracted her.
Alarm and Aggression Calls
Anna’s hummingbirds communicate alarm by making a sharp “chip” sound. They typically make this call when a potential predator approaches the nest. It functions to alert other hummingbirds to danger.
Both males and females use the chip call when defending nests or feeding territories. They dive-bomb intruders while making this call to signal aggressiveness and a willingness to attack.
One study on Anna’s hummingbirds found that the pitch of alarm calls indicates the level of threat. Higher-pitched alarm calls are associated with more alarming disturbances, like human intruders, as opposed to lower-pitched chip calls for less threatening intruders like other birds.
Contact Calls
Anna’s hummingbirds also make simple contact calls referred to as “chatters.” These are very short, repetitive chips and squeaks.
Young hummers will chatter softly and almost continuously when they are waiting in the nest for a parent to arrive with food. This helps the parent locate the nest and delivers food more efficiently.
Adults also use contact calls in flight. The repetitive chip notes allow individuals in a flock to maintain communication and cohesion while flying or foraging.
Other Sounds
In addition to communicative noises, the wingbeats of hummingbirds in flight create a humming, buzzing, or fluttering sound. The wings beat incredibly fast to enable hummingbirds to hover and fly in all directions.
The aerodynamics of these wing movements generates the characteristic humming noise that gives the birds their name. The pitch of the hum varies based on body size and the speed of wing-flapping.
Anna’s hummingbirds also make non-vocal sounds by snapping their bills together rapidly. They create this sound during courtship displays or aggressive encounters. It likely serves to intimidate rivals or impress potential mates.
How Do Hummingbirds Produce Sound?
Hummingbirds like Anna’s hummingbirds have specially adapted syrinxes that enable them to produce sounds.
The syrinx is the sound-producing vocal organ in birds, located at the branch point between the trachea and bronchi. The syrinx contains vibrating tissues and membranes that oscillate to produce noise when air passes through.
In hummingbirds, the syrinx can oscillate extremely rapidly. Specialized syringeal muscles allow hummingbirds to control the frequency, intensity, and rhythm of their vocalizations.
By contracting the syringeal muscles in different ways, hummingbirds can create diverse sounds from high-pitched squeaks to lower-pitched buzzes.
The syrinxes of hummingbirds also allow them to vocalize at frequencies above the range of human hearing. Many of their communication sounds contain these ultrasonic components.
Why Do Hummingbirds Make Sounds?
Hummingbirds like Anna’s hummingbirds have several key reasons for vocalizing:
- Attracting mates
- Defending territories
- Communicating alarms
- Staying in contact with flock mates
- Begging for food from parents
Their diverse vocalizations allow for effective communication in all these different contexts.
The sounds made by their specialized syrinxes and the aerodynamics of their wings have likely evolved to facilitate communication despite the small size of hummingbirds.
High-pitched squeaks are easier for small birds to produce efficiently and also travel farther than lower frequencies. And by using non-vocal sounds like snaps and wing hums, hummingbirds can communicate without expending energy vocalizing when not necessary.
Mimicry
Some species of hummingbirds can mimic sounds they hear in their environment. For example, Anna’s and Allen’s hummingbirds sometimes learn to incorporate mellifluous tweets, whistles, or warbles heard from other birds into their own vocalizations.
This mimetic ability is not as advanced as famously mimicking birds like parrots or mynahs. But it does provide evidence that hummingbirds have flexible sound production and can voluntarily imitate novel sounds.
How Do Humans Perceive Hummingbird Sounds?
Humans cannot hear many of the ultrasomatic frequencies used by hummingbirds for communication. However, we can detect some of their vocalizations, like alarm and contact chips.
The buzzing dive sounds and wing hums produced by Anna’s hummingbirds during courtship are also audible to humans. These frequencies tend to be on the lower end of the hummingbird vocal range, which is why they are perceptible to us.
When recording hummingbird sounds to play back and analyze, it is necessary to use specialized high-speed, high-frequency recording equipment to capture the full spectrum of their vocalizations.
Standard recording devices designed for human speech will miss many of the higher-pitched components because they record only up to 8-10 kHz, while hummingbird sounds can reach 12-20 kHz.
Unique Adaptations
The Anna’s hummingbird has several unique adaptations related to sound production:
- Syrinx muscles allowing for very high frequency and rapid frequency modulation ability
- A pendant windpipe that allows for greater amplitude modulation
- Thin, blade-like wings that maximize wingbeat sounds
- Rapid bill snapping behavior used to generate sounds
These specializations all contribute to the Anna’s hummingbird’s ability to produce intricately modulated, non-harmonic, ultrasonic vocalizations.
Recording Hummingbird Sounds
To fully record the complexity of hummingbird sounds, specialized high-speed recording equipment is required. Key features of proper hummingbird recording gear include:
- High sample rate (192+ kHz)
- 24-bit depth resolution
- Wide frequency response (flat up to 20 kHz)
- High sound pressure handling (130+ dB SPL)
- Built-in shock mounting
High-sensitivity omnidirectional mics or small lavalier mics work well for field recordings and minimize noise interference. Shotgun mics can also isolate vocalizations from background noise.
It’s best to use multiple recorders and position mics very close to hummingbird display areas. Getting within 6 feet improves the signal-to-noise ratio of rapid syrinx modulations that attenuate over distance.
Conclusion
The Anna’s hummingbird produces a range of buzzes, chips, chirps, and chatters for communication purposes. These vocalizations are facilitated by specialized adaptations like syringeal muscles, rapid bill clapping, and wing aerodynamics.
Recordings require high sample rate audio gear to capture the full spectrum of hummingbird sounds. When properly recorded and analyzed, we can appreciate the intricacy and nuance of hummingbird vocal communication.
