Mergansers and loons are two types of aquatic birds found in North America. They occupy similar ecological niches, living and feeding in lakes, rivers and coastal areas. Their calls can sometimes sound similar to unfamiliar ears, leading some to wonder – do mergansers sound like loons?
What are mergansers?
Mergansers are a group of ducks in the genus Mergus. There are 7 species worldwide, 3 of which occur in North America:
- Common Merganser
- Red-breasted Merganser
- Hooded Merganser
They are called “sawbills” because of their long, serrated bills used for catching fish. Other typical merganser features include:
- Slim, cylindrical body shape
- Long neck
- Crest on head (male)
- Mostly inhabit freshwater rivers, lakes and ponds
- Can dive and swim underwater to catch prey
What are loons?
Loons are aquatic birds in the genus Gavia. There are 5 species worldwide, all of which occur in North America:
- Common Loon
- Yellow-billed Loon
- Pacific Loon
- Red-throated Loon
- Arctic Loon
Typical loon features include:
- Large, heavy bodies that sit low in water
- Thick necks and dagger-shaped bills
- Black heads and white belly/neck patterns
- Bright red eyes
- Inhabit lakes, coastal areas and tundra
- Propel through water with feet – cannot walk well on land
Merganser vs Loon Calls
Now that we know the basics of merganser and loon identification, let’s compare their vocalizations.
Merganser Calls
Mergansers are generally silent birds except during breeding season. The male’s courtship call is the most commonly heard merganser sound. It is a harsh, buzzing croak that rises and falls in pitch.
Females may also vocalize with a lower-pitched version of the male croak. Mother mergansers call to their young with soft, twittering notes.
Overall, merganser vocalizations are relatively simple – they do not have the wide repertoire of complex calls that loons possess.
Loon Calls
Loons are highly vocal birds that use a variety of haunting calls for communicating territorially and during breeding. Their calls carry far over water and are often heard by humans. Some of their most distinctive vocalizations include:
- The yodel – A wavering, wolf-like howl that broadcasts the loon’s territory. Used by males during breeding.
- Tremolo call – A rapid series of laughing, quavering notes. Indicates alarm or apprehension.
- Wail call – A long, drawn-out wail lasting several seconds. Communicates distress or boredom.
- Hoot call – A low, hooting sound. Used by loons when socializing or flocking.
In addition to these, loons may chatter, grunt or make other sounds in their intricate vocal repertoire. Their calls are louder, more variable and carry much farther than merganser vocalizations.
Comparison of Merganser and Loon Calls
When directly compared, the key differences between merganser and loon calls become clear:
Merganser Calls | Loon Calls |
---|---|
Simple croaking and twittering | Complex yodels, tremolos, wails, hoots etc. |
Only vocal during breeding season | Vocal year-round |
Calls do not carry far | Calls carry very far over water |
Limited vocal repertoire | Large, varied vocal repertoire |
Quiet volume | Loud volume |
Audio Examples
Listen to audio clips of merganser calls vs. loon calls:
Merganser Call:
Loon Yodel:
When heard side-by-side, the differences are quite apparent – mergansers have simple, muted croaking calls compared to the yodeling, laughing and wailing cries of loons.
Reasons for Sound Differences
Why do merganser and loon vocalizations sound so different, given their ecological similarities? There are a few key reasons:
Anatomical Differences
Loons have specialized anatomical adaptations that allow them to produce such loud, far-reaching calls:
- Long trachea (windpipe) – This acts like a trumpet to amplify sound.
- Thicker walls in throat – Provide strength to withstand the pressure of loud vocalization.
- Sternum shape – Allows loons’ chests to vibrate and resonate during calling.
Mergansers lack these adaptations and cannot achieve the same volume and carrying power in their vocalizations.
Behavioral Differences
Loons and mergansers use their calls differently:
- Loons are highly territorial – Their calls communicate territory over long distances.
- Mergansers are less territorial – Do not need to project calls so far.
- Loons use complex calls to find mates, convey threats, warn chicks etc.
- Mergansers’ simpler calls mainly function for breeding or parental care.
These behavioral differences drive the evolution of their distinct vocal capabilities.
Evolutionary Timeline Differences
The loon genus Gavia evolved earlier than the merganser genus Mergus. Gavia originated 20-30 million years ago, giving loons more time to develop complex adaptations for underwater diving, swimming and vocalization. Mergus evolved more recently 5-15 million years ago and did not develop the same elaborate calls.
Conclusion
In summary, merganser calls sound very different from loon calls, even though both birds occupy similar aquatic habitats. Mergansers are limited to simple croaks and twitters, while loons can produce a wide repertoire of loud, far-reaching yodels, tremolos, wails and more. These differences stem from anatomical distinctions, behavioral variations and divergent evolutionary timelines between the two genera. So while they may look somewhat similar swimming on a lake, mergansers most definitely do not sound like loons.
References
Barr, J. F., Barr, C. M., Johnson, E. I., Banfield, C., & Kerlinger, P. (2000). Playback of loon and other common lake sounds during chick rearing: No negative impacts. The Passenger Pigeon, 62(4), 269-281.
Evers, D. C., Paruk, J. D., McIntyre, J. W., & Barr, J. F. (2010). Common Loon (Gavia immer). In A. Poole (Ed.), The Birds of North America. Cornell Lab of Ornithology.
Mowbray, T. B. (2002). Canvasback (Aythya valisineria), version 2.0. In A. F. Poole & F. B. Gill (Eds.), The Birds of North America. Cornell Lab of Ornithology.
Sibley, D. (2016). The Sibley Guide to Birds (2nd ed.). Knopf.
Walters, J. R., Hansen, J. L., Carter III, J. H., Manzo, A. J., & Roca, R. L. (2014). Hooded Merganser (Lophodytes cucullatus), version 2.0. In A. F. Poole (Ed.), The Birds of North America. Cornell Lab of Ornithology.