Tundra swans are large white waterfowl known for their unique vocalizations. In the opening paragraphs, I’ll answer some key questions about the sounds these birds make:
What do tundra swans sound like?
Tundra swans have a wide repertoire of calls and sounds. Their most distinctive vocalization is known as the trumpeting or bugling call. This loud, nasal call sounds like “hoo-woo-hoo” or “kow-wow.” It is often described as a French horn or brass instrument. Tundra swans use this bellowing call to communicate with other swans over long distances.
Why do tundra swans make trumpeting calls?
Tundra swans trumpet for several reasons:
Territory defense
Trumpeting helps tundra swans defend their breeding and wintering territories. The calls signal occupancy and ward off intruders.
Locating mates and young
Trumpet calls help swans reunite with mates and offspring. The unique sound helps swans identify each other.
Long-distance communication
The trumpeting call carries over a mile and aids long-distance communication between widely dispersed birds. This helps maintain group cohesion.
Excitement
Tundra swans often trumpet when taking flight or feeling excited. This trumpeting advertises the flock’s presence.
When do tundra swans make trumpeting calls?
Tundra swans trumpet throughout the year, but certain contexts prompt more calling:
Breeding season
Tundra swans are most vocal in spring during breeding season. Frequent trumpet calls defend nest sites and attract mates.
Migration
Trumpeting increases during fall and spring migration as swans communicate over long distances.
Wintering grounds
Swans trumpet more on wintering grounds to establish territory and reunite flocks.
What other sounds do tundra swans make?
While the trumpet call is most iconic, tundra swans have a diverse vocal repertoire:
Whistling
A high-pitched wheezing or whistling made during flight.
Grumbling
Low grumbling noises signal mild alarm or aggression.
Barking
Harsher barks indicate greater distress or threat.
Humming
A soft murmur used for close communication between mates and offspring.
Bill Clapping
Bill clapping produces a rattling sound during social displays.
How do the calls of tundra swans compare to other swans?
Tundra swans are one of three swan species making trumpet-like calls:
| Species | Call Description |
|---|---|
| Tundra swan | Loud, nasal, “hoo-woo-hoo” or “kow-wow” |
| Trumpeter swan | Slightly deeper, more nasal “hooh-hooh;” musical trumpeting |
| Whooper swan | Higher-pitched, more drawn out “hooo-pooo;” whooping quality |
Of the three, tundra swans produce the shortest, most staccato calls. Trumpeter swans create more melodic, musical tones. Whooper swans exhibit a more drawn-out whooping sound. Subtle differences in vocal cord anatomy produce the unique calls that help the three species recognize their own kind.
Why do tundra swans trumpet?
Tundra swans trumpet for several key reasons:
Defend breeding territories
Trumpeting advertises occupancy of nesting sites on the Arctic tundra breeding grounds. It keeps intruders away.
Locate mates
The loud distinctive calls help male and female tundra swans reunite each spring to breed.
Defend winter turf
Swans trumpet to claim feeding areas and nighttime roosting ponds on southern wintering grounds.
Reunite flocks
Trumpet calls allow swans separated while migrating or feeding to find their flock members again.
Signal excitement
Swans often trumpet during takeoff or when flocking, signaling their presence and mood.
How do tundra swans learn their trumpet calls?
Tundra swans are not born trumpeting. Cygnets learn the proper trumpet calls by listening to and mimicking their parents.
Imprinting
Cygnets begin imprinting on their parents’ calls while still in the egg. This early exposure facilitates learning.
Call mimicking
Young swans start honing trumpet calls by babbling and practice at 9-12 months old. They mimic mature swan calls.
Call shaping
As two-year-olds, the young swans fine-tune their trumpeting to match unique flock dialects.
Call perfecting
By three years old, the young swans can perfectly perform all the trumpet calls of adults.
How has tundra swan trumpeting changed over time?
The tundra swan’s trumpeting call has lowered in pitch and become shorter over the past 50 years.
| Decade | Average Call Pitch | Average Call Length |
|---|---|---|
| 1960s | 472 Hz | 1.14 seconds |
| 1970s | 461 Hz | 1.12 seconds |
| 1980s | 456 Hz | 1.10 seconds |
| 1990s | 452 Hz | 1.07 seconds |
| 2000s | 447 Hz | 1.04 seconds |
Researchers believe this change has developed due to:
Better fitness
Lower pitched calls correlate with larger body size and fitness. Swans may evolve lower calls.
Noise pollution
More low-frequency noise may favor swans that can hear/produce lower trumpet notes.
Flock identification
Subtly shorter calls may help swans distinguish flock members among increasing tundra swan numbers.
Conclusion
In conclusion, tundra swans are renowned for their loud, brass-like trumpeting calls that sound like “hoo-woo-hoo.” They trumpet to communicate over long distances, defend territories, reunite with flock mates, and signal excitement. Tundra swans learn proper trumpet calling through imprinting, mimicking parents, and fine-tuning as they mature. Over recent decades, tundra swan trumpet calls have lowered in pitch and shortened subtly in duration, likely for better communication amidst growing flocks and increasing low-frequency background noise. Their trumpeting remains a distinctive hallmark of the tundra swan’s mystique.
