The familiar “quack” is often the only sound associated with ducks, but their communication repertoire is far more complex. Ducks are highly vocal birds that utilize an array of sounds beyond a simple call. Their diverse soundscape includes whistles, grunts, coos, and even mechanical noises, each serving a specific social or environmental purpose. These vocalizations allow ducks to coordinate flock movements, attract mates, warn of danger, and maintain family bonds.
The Classic Quack: Context and Gender Differences
The loud, sustained “quack” is primarily produced by the female Mallard, or hen. This call is technically known as the decrescendo call, characterized by its loud start and fading conclusion. Female Mallards use this sound as a long-distance contact call, helping to announce their location or attract a mate. It also functions as a territorial advertisement when searching for a nest site.
Male Mallards, or drakes, do not produce the same loud quack due to differences in their vocal anatomy. The male’s sound is typically a much quieter, lower-pitched, and often raspy sound. This muted, guttural noise is sometimes described as a low grunt.
Non-Quacking Vocalizations: Signals of Intent
Beyond the classic quack, ducks employ non-quacking vocalizations to convey specific messages. Male ducks rely on whistles and grunts for courtship displays. For instance, the male Mallard produces a specialized grunt-whistle call, often accompanied by a head-bobbing display, to attract a hen. These sounds are typically high-pitched and tonal, distinct from the female’s throaty calls.
Alarm and distress signals are communicated through sharp, loud squeals or shrieks designed to startle and alert the flock. Mother ducks use softer, rhythmic sounds, like a quiet trill or piping, to communicate with their young. This consistent vocalization helps ducklings follow their mother and reassures them of her presence.
How Species and Sex Influence Duck Sounds
The variety of duck sounds is rooted in species-specific evolution and sexual dimorphism in vocal anatomy. The sounds described above are not universal, as many species of ducks rarely quack at all. Dabbling ducks, like the Mallard and Pintail, tend to be more vocal with quacks and whistles compared to diving ducks, such as Scaup or Eiders.
The male Northern Pintail is known for a delicate, high-pitched “prreep-prreep” whistle. In contrast, the male Eurasian Wigeon produces a distinctive, breathy, two- or three-note whistle. The Muscovy duck is a vocal outlier, with males producing a breathy hiss and females a quiet, trilling coo instead of a traditional quack.
This divergence is explained by a specialized bony structure in the male’s syrinx, the avian voice box. Male ducks possess a structure called the bulla, a hollow capsule located near the syrinx. This bulla acts as a Helmholtz resonator, modifying the sound produced by the vibrating membranes. The resonance chamber dampens the loudness and changes the frequency, resulting in the characteristic raspy or whistling calls of the drake.
Sounds Not Made by the Voice Box
Not all communication sounds originate from the syrinx, as many physical actions also create noise that conveys information. Certain species produce distinct sounds with their wings during flight. The Common Goldeneye, for example, creates a “whistling” sound as it flies. This mechanical sound serves as a form of non-vocal communication, often alerting others to the bird’s presence or movement.
Ducks also use their bills and bodies to create noise, particularly during feeding or aggressive interactions. The clicking or rattling sound of a bill rapidly sifting water is common when dabbling ducks feed. Loud splashing and water noises are also incorporated into aggressive displays or courtship rituals.