Walruses are large marine mammals inhabiting the cold waters of the Arctic and subarctic. These social creatures, known for their prominent tusks and whiskered snouts, spend significant portions of their lives on sea ice and in shallow coastal waters. Walruses are particularly notable for their complex array of vocalizations, which contribute to their unique presence in the Arctic soundscape. While many might wonder if walruses truly “whistle,” their vocal repertoire encompasses a much broader and fascinating range of sounds.
The Unique Soundscape of Walruses
Walruses produce a diverse collection of sounds, encompassing growls, barks, grunts, clicks, rasps, and even soft whistles. While the term “whistle” might capture some of their higher-pitched sounds, it does not fully represent their acoustic range. Male walruses are known for distinctive bell-like sounds, often described as metallic or gong-like. These resonant calls are produced underwater. Their vocalizations span a broad frequency range, from approximately 100 Hz to 10 kHz.
How Walruses Produce Their Calls
Walruses possess vocal cords and produce sounds both above and below the water’s surface. Their sound production involves specialized inflatable air sacs called pharyngeal pouches. These pouches, located on either side of the esophagus, can expand to hold up to 50 liters of air. This anatomical adaptation allows them to create the resonant, bell-like sounds characteristic of their underwater vocalizations.
Beyond vocalizations involving air, walruses also produce sounds through physical actions. Male walruses generate rhythmic sounds by clapping their fore flippers together underwater. This clapping behavior produces acoustic impulses by cavitation. These non-vocal sounds contribute to their diverse communication methods.
The Meaning Behind Walrus Vocalizations
Walrus vocalizations serve important functions within their social structures. Sounds are used for general communication, helping to maintain contact within groups and identify specific animals. For example, mother walruses and their calves recognize each other through distinct vocal cues, with the bond persisting for several years. Walruses also use sounds to signal alarm when disturbed by potential threats.
During the breeding season (December to March), male walruses utilize an extensive repertoire of sounds as part of their courtship displays. Males produce complex underwater songs consisting of knocks, taps, pulses, and bell-like sounds to attract females and establish dominance among rivals. These vocal displays can be prolonged, lasting for hours or even days. Whistling is also a part of male courtship and dominance displays, with louder, lower-pitched whistles often asserting dominance. The intensity and persistence of these vocalizations can indicate a male’s physical fitness, and walrus sounds may also play a role in navigation and locating prey on the seafloor.