Most reptiles are known for being generally quiet, so the idea of a lizard making noise is often unexpected. While many lizard species rely on visual displays and chemical cues for communication, a select few are highly vocal. These sounds range widely, from simple, unmodulated noises used for defense to complex, structured calls that serve a communicative purpose.
Hissing, Puffing, and Other Defensive Sounds
The most common sounds produced by lizards are simple, defensive noises generated by the forceful movement of air. Hissing is a widespread reptilian threat display created by rapidly expelling air from the lungs through the glottis. This sound is a mechanical noise, not a true vocalization, as it does not rely on specialized vocal cords. Larger species, such as monitor lizards and iguanas, frequently use a loud, sustained hiss to deter potential predators.
Hissing is often paired with a visual display to maximize its effect. Many lizards will simultaneously puff up their bodies to appear larger and more intimidating, which increases the volume of the air expulsion. The combination of a sudden, loud sound and an exaggerated body size is an effective anti-predator strategy. Other non-vocal sounds, like tail thrashing or slapping against the ground, are also used in defensive and territorial contexts.
Lizards Known for Complex Vocalizations
Lizards in the Gekkonidae family are renowned for producing complex, true vocalizations. Unlike most other lizards, geckos possess specialized structures within their larynx, including true vocal cords, which allow them to modulate sound frequency. This structural difference enables geckos to generate a wide repertoire of complex noises, including chirps, clicks, barks, squeaks, and loud distress screams.
These vocalizations have a clear harmonic structure and are not simple air expulsions. The Tokay gecko (Gekko gecko) is famous for its loud, distinctive mating call that sounds like “to-kay,” which is the source of its common name. Specific calls, known as advertisement calls, are species-specific and convey information about the individual’s identity and condition. While geckos are the most vocal group, a few other species, like certain skinks or lizards in the genus Anolis, also produce structured vocalizations, often as distress calls.
Why Lizards Make Noise
Lizard sounds serve a few primary functions. The most obvious function is defense and distress, which is the primary use for simple hissing and screaming sounds. A sudden, loud hiss or shriek can startle a predator, allowing the lizard a brief window of opportunity to escape. These broadband distress calls are simple in structure and designed to be universally alarming.
Acoustic signals are also employed for territoriality and competition. Male geckos use their complex advertisement calls to warn off rival males and establish dominance over a claimed area. By vocalizing their presence, they can often avoid a physical confrontation, which conserves energy. These same complex calls also play a role in mating, where males use specific chirps and clicks to attract females and signal reproductive readiness.