Whales are vocal creatures. Sound serves as a primary sense, crucial for survival and interaction within the marine environment. Unlike land mammals that rely heavily on sight, whales navigate and perceive their surroundings through acoustic signals, as light penetrates water poorly and smell is limited. Sound travels approximately four times faster in water than in air, making it an efficient medium for communication and sensing.
The Variety of Whale Sounds
Whales produce diverse sounds. Toothed whales (e.g., dolphins, sperm whales) emit high-frequency clicks: short, sharp, and rapid. These clicks are primarily used for echolocation, mapping surroundings. They also produce melodic whistles for social contexts, and rhythmic pulsed calls indicating mood or group cohesion.
Male humpbacks are known for complex, intricate “songs”—structured sequences of varying frequencies and patterns that can last for hours and repeat over days. Baleen whales (e.g., humpbacks, blue whales, fin whales) generate lower-frequency sounds. Their repertoire includes moans, grunts, thumps, and knocks (20-200 Hz).
How Whales Make Sounds
The mechanisms for sound production differ between toothed whales and baleen whales. Toothed whales (odontocetes) generate high-frequency clicks and other vocalizations by forcing pressurized air through specialized nasal structures called “phonic lips” or “monkey lips.” These tissues vibrate, creating sound. The sound signal then travels through the melon, a fatty organ in their forehead, focusing and directing the sound beam.
Baleen whales (mysticetes) produce low-frequency sounds and complex songs using a larynx-like structure. Unlike land mammals, they do not possess traditional vocal cords. Recent research indicates baleen whales evolved unique internal laryngeal structures, including a U-shaped tissue ridge and specific cartilages, to generate sound. This mechanism allows them to produce sound by recirculating air within their bodies, preventing water from entering airways.
Why Whales Vocalize
Whales vocalize for essential purposes, reflecting sound’s importance in aquatic lives. Communication is a primary function, enabling whales to interact, maintain group cohesion, and foster bonds between mothers and calves. Different vocal “dialects” can exist among pods of the same whale population, aiding identification.
Echolocation, primarily used by toothed whales, is a sophisticated method for navigation and orientation. By emitting clicks and interpreting echoes, these whales construct a detailed acoustic map of their environment, locating objects, identifying threats, and navigating in dark or murky waters. Sound also plays a role in hunting and foraging; some whales use vocalizations to locate prey, while others coordinate calls during group hunting.
Mating and reproduction are significant drivers of whale vocalization, particularly the elaborate songs of male humpback whales. These complex songs are often associated with courtship and may signal a male’s fitness. Some sounds serve as warning signals or territorial claims. Whales may also use physical actions like tail or fin slapping to convey aggression or gather prey.