Chimney swifts (Chaetura pelagica) are small, cigar-shaped birds that are known for their unique chittering and twittering vocalizations. As their name suggests, chimney swifts often roost and nest inside chimneys and other vertical structures. When flying in large flocks, the cumulative noise of dozens or hundreds of calling swifts can create quite a chatter!
Chimney Swift Calls and Vocalizations
Chimney swifts have a variety of vocalizations they use to communicate. Some of their more common calls include:
Chittering
The most characteristic chimney swift vocalization is a rapid, repetitive chittering or twittering noise. This almost insect-like call is thought to help maintain contact between flock members as they fly and forage together. Chittering may also play a role in courtship displays. The chittering call is produced almost constantly when swifts are active and flying.
Screeching
Chimney swifts can produce loud, screeching alarm calls when disturbed or defending their nest sites. These screeches are sharp and piercing and can sound metallic or mechanical to human ears. Screeching often occurs when swifts feel threatened by predators or intruders.
Begging Calls
Swift nestlings (baby birds) vocalize with repetitive, raspy begging calls when requesting food from their parents. These sounds start out soft but become louder and more insistent as the nestling gets hungrier! The begging calls help guide parent swifts to feed the correct chick.
Chattering
Groups of chimney swifts may create a loud, fast-paced chattering noise just before entering a chimney roost for the night. This communal chattering is thought to help synchronize the birds before they spiral down together into the chimney shaft.
Bow Call
Male chimney swifts perform a unique “bow call” display during courtship and pair bonding. While flying, the male swiftly ascends and then plunges downward while making a pulsating “wuuuut” vocalization.
When and Why Chimney Swifts Vocalize
Chimney swifts vocalize in various social and behavioral contexts. Some examples include:
- Chittering is used almost constantly when swifts are actively flying and foraging to maintain contact.
- Alarm calls and screeches are emitted to ward off potential threats near nests or roosts.
- Begging calls by nestlings summon parent birds to deliver food.
- Chattering may help synchronize flock movements such as entering a communal roost.
- Courtship displays like the bow call help attract and bond mates.
- Swifts may vocalize more around nesting and roosting areas to locate flock mates.
- Calls become more frequent when reacting to disturbances near the nest or roost.
In general, the most chatter occurs when chimney swifts are congregating in large flocks, such as at pre-roost gatherings or foraging aggregations. Vocalizations play an integral role in maintaining social cohesion in these fast-flying birds.
Description of Chimney Swift Vocalizations
Here are some more details about the sounds and acoustics of common chimney swift vocalizations:
Chittering Call
- Rapid series of 8-20 notes per second
- High pitched with a buzzing, insect-like quality
- Notes have a uniform shape and delivery
- Series lasts 1-3 seconds and is repeated constantly
- Resembles the call of certain crickets or cicadas
- Produced on both inhalation and exhalation
- Thought to be produced by specialized feathers that act as reeds
Screeching Alarm Call
- Loud, piercing, raspy scream
- Lasts about 0.5 seconds
- Broadband noise with a wide frequency range
- Sounds metallic or mechanical to human ears
- Given both singly and in groups if threat persists
- Highly responsive threat call to disturbance
Begging Call
- Raspy, buzzing quality
- Pattern is repetitive series lasting 1-3 seconds
- Notes increase in amplitude over the series
- Series repeated every 4-6 seconds, intensifying if no food arrives
- Noisy with broad frequency range
- Persistence signals level of hunger to parent birds
Chattering Communal Roosting Call
- Loud, fast, nasal chatter
- Harsh, mechanical sounding quality
- Narrow frequency range centered around 2-4 kHz
- Highly rhythmic delivery
- Birds chattering simultaneously in the flock
- May help birds synchronize before entering chimney
Chimney Swift Song Versus Call
Unlike many songbirds, chimney swifts do not have true songs. Songbirds like finches and sparrows have complex songs used to define territories and attract mates. Chimney swifts do not have this ability and only make simpler calls.
Swift calls serve more utilitarian purposes like maintaining contact, begging, or signaling alarm. The male’s bow call display is the vocalization in swifts that comes closest to a true song, although it is still simple in structure. It is primarily used only by males in mating contexts.
Mimicking Chimney Swift Vocalizations
The unique vocalizations of chimney swifts can be tricky to mimic accurately with the human voice. However, trying to imitate their sounds can be a fun challenge!
To mimic the chimney swift’s chatter call, try making a very fast stuttering or buzzing with your tongue. Raise the pitch of your voice and make the sounds as rapid as possible, like a high-pitched insect call. Practicing while jogging in place can mimic the energy of swifts on the wing.
For the screech call, simply cry “seeeeEEEE!” while slidings your voice quickly up in pitch towards the end. Capture the abruptness and urgency chimney swifts convey when alarmed.
Begging calls can be approximated by a drawn-out, hoarse “zzzziiiiiiiiip” that increases in volume and emphasis. Capture the needy urgency and repetitive nature of real swift nestlings.
While not perfect imitations, trying to mimic chimney swifts vocalizing can give you an appreciation for the unique sounds these aerial acrobats make!
Recordings and Audio of Chimney Swift Vocalizations
Hearing actual chimney swift vocalizations is the best way to get familiar with their diverse sounds. Here are some good online resources with chimney swift audio recordings:
- Chimney Swift Sounds – All About Birds Cornell Lab – Includes both chittering and screech calls
- Chimney Swift Recordings – Xeno-Canto – Collection of chimney swift call recordings from around the world
- Chimney Swifts Chittering – YouTube video with good chimney swift chatter sounds
These recordings showcase the diversity of vocalizations chimney swifts use to communicate and interact. Listen closely to appreciate the unique sounds of these aerial acrobats!
Mimicry Using Chimney Swift Vocalizations
Some other bird species mimic or imitate the vocalizations of chimney swifts, likely because swifts occur in large flocks and serve as a good model to copy. Documented chimney swift vocal mimics include:
White-throated Swift
White-throated swifts overlap part of their range with chimney swifts and have been observed mimicking their chatter calls. Since both are aerial swifts, white-throateds can convincingly imitate the vocalizations of chimney swifts.
Eastern Phoebe
Eastern phoebes will sometimes copy the chatter or begging calls of chimney swifts, especially near chimneys or nest sites where swifts are present. Phoebes are accomplished vocal mimics of many species.
Northern Mockingbird
Mockingbirds excel at pick up on the sounds of any species they live around, including chimney swifts. A mockingbird near a chimney swift roost may incorporate their screams, chatter, and begging calls into its repertoire.
Brown Thrasher
Like mockingbirds, brown thrashers are amazing mimics and have been documented replicating chimney swift chittering and begging calls in areas where they co-occur with these swifts.
The social, flocking nature of chimney swifts seems to lend itself well to vocal mimicry by other smart, opportunistic bird species.
Conclusion
Chimney swifts have a diverse array of vocalizations that serve important functions for communicating and sticking together in aerial flocking flocks. Their chittering chatter serves as their characteristic call, while screeches, begging calls, and communal roosting chatter help facilitate other social behaviors for these highly gregarious birds. While not songbirds, the vocal repertoire of chimney swifts is varied and fascinating. Listening to recordings of chimney swifts grants unique insight into the sounds that make up the audible world of these aerial acrobats.