While many snakes are perceived as silent, many species produce distinct sounds. These sounds serve specific functions, often as communication or a warning. The auditory world of snakes is more complex than a simple hiss, encompassing unique methods of sound production.
The Primary Sounds of Snakes
The most widely recognized snake sound is hissing, which involves a forceful expulsion of air. This sound can vary in intensity and pitch among different species, serving as a general alert.
Beyond the common hiss, some snakes, particularly rattlesnakes, produce a distinctive rattling sound. This unique noise originates from specialized segments at the end of their tails, creating an unmistakable acoustic warning.
Puffing or blowing is a more explosive exhalation, sometimes used as a threat display. Other species exhibit less common sounds. For instance, the King Cobra is known to produce a low-frequency growl, a sound different from a typical hiss. Some snakes, like the saw-scaled viper, generate a rasping or sizzling noise by rubbing their scales together. Corn snakes may whistle, while pine snakes are noted for a shrieking sound.
How Snakes Produce Their Sounds
Snakes do not possess vocal cords, unlike mammals, birds, or other reptiles that use them for complex vocalizations. Instead, they rely on alternative physiological mechanisms to generate sounds. Hissing and puffing sounds are created by forcing air rapidly through the glottis, an opening to the trachea or windpipe located in the snake’s throat. As air is expelled, a piece of cartilage within the glottis vibrates, producing the characteristic sound. Snakes can also expand their rib cages to take a deep breath, providing a reservoir of air to sustain a hiss for a longer duration and control its volume and pitch.
Rattlesnakes rattle by rapidly vibrating hollow, interlocked keratin segments at their tail tips. When the snake rapidly shakes its tail, these segments strike against each other, creating the distinct sound. Specialized muscles in their tails allow rattlesnakes to control this movement and produce the warning sound. Some snakes, like the saw-scaled viper and the African egg-eating snake, generate sound through stridulation by rubbing specialized, rough scales on their bodies together, producing a sound akin to a sizzle or rasp. An exception to the lack of vocal cords is found in pine snakes, which possess a laryngeal septum that functions similarly to a single vocal cord, enabling them to produce a unique shrieking or growling sound.
The Purpose Behind Snake Sounds
The primary function of most sounds produced by snakes, such as hissing, rattling, and rasping, is warning and defense. These sounds serve to deter potential predators or perceived threats, indicating that the snake feels agitated and prefers to avoid physical confrontation. The sound acts as a clear signal to “back off,” allowing the snake to conserve energy that would otherwise be expended in a direct fight.
Snake sounds are often part of a larger threat display, which can include body posturing like coiling, body flattening, or head raising. This combined display aims to make the snake appear more intimidating. Some non-venomous snakes also employ acoustic mimicry, imitating the sounds of dangerous species to ward off predators. For example, gopher snakes may vibrate their tails to mimic the sound of a rattlesnake, even without a rattle. These auditory signals are not complex vocal communication between snakes, but direct messages intended to deter threats and facilitate self-preservation.