Out Of 6,000 Lizard Species, Only One Can Vocalise – Here Is How Geckos Got Their Voice

Did you know that there are more than 7,000 lizard species in the world that live on all continents of the Earth except Antarctica? The amazing thing about these reptiles is that they do not have vocal cords like other animals.

The majority of these reptiles, including chameleons, iguanas, and monitor lizards, are very silent animals that interact with one another through body language and scents. But hold on, there is something interesting for you to know. The only lizard in the world that can bark, click, and squeak is the Gecko.

Geckos: The Only Talking Lizard on Earth

Trivia: The white lizard in your house is also a gecko, referred to as a common house gecko.

Geckos are small carnivorous lizards that fall under the suborder of Gekkota and the clade Gekkonomorpha. These lizards are found in all parts of the world, from South America to the vast regions of Europe and Asia.

They live in hot climatic conditions and are between 1.6 and 67 cm (0.6 to 26.4 inches) long. These lizards are the most diverse group of lizards. There are about 2,000 different species of geckos.

The gecko is a relative of the skink and the legless lizards. This lizard falls under a special classification of reptiles.

Unlike all their relatives who make hissing and puffing sounds by expelling air forcefully from the lungs, geckos are the only kind of lizards that make vocal sounds of chirping, clicking, barking, and squeaking.

How Does a Gecko Make Sound? (The Three Different Call Types Scientists Discovered)

Unlike other silent reptiles, geckos generate vocal sounds using air that passes through their lungs and vibrates against specialised vocal cords located in the larynx (vocal organ). The scientists who have researched geckos' vocal sounds have identified them into three categories:

How It Works inside the Body

• Air flow: Gecko expels air from its lungs very quickly.
• Vibration: This air then moves through elastic folds in its larynx.
• Sound Production: Gecko changes the frequency and amplitude of sound by adjusting its mouth aperture and throat position.

This is a very small and unique feature in the body of a gecko, which makes it a talking lizard in the world.

Why Can Geckos Talk When 5,000 Other Lizard Species Stay Silent?

In total, out of the 5,000 to 6,000 species of lizards found to date, most of them do not produce any sounds except for hissing sounds. However, geckos are unique among lizards in that they can produce sound.

The Key Evolution Factors

• Nocturnal Behaviour (Nocturnality): Most of the geckos are nocturnal animals. The visual signals such as the use of coloured neck fans and head-bobbing signals do not function without light. Hence, geckos developed auditory signals.
• Structure of Vocal Cords: Geckos possess flexible vocal cords inside an extremely complicated larynx which is absent in other lizard families.
• Adaptation of Auditory Senses: Geckos have developed a complex inner ear that responds to sound frequency.

Chirping for Territory, Barking for Mates: What Geckos Are Really Saying

Source: Flickr

While random sounds are produced by the geckos, all the sounds produced by the geckos have a definite social message attached to them.

Decoding the Sounds Produced

Through variation in tone and pitch, geckos send messages in the dark.

1. For attracting mates

• The Message: "I am fit and here to attract you!"
• The Sound: Constant barking and chirping sounds. "To-Kay" geckos, which produce "to-kay" mating calls, get their names from these sounds.

2. Territorial Boundaries

• The Message: "This is my territory. Don't come closer!"
• The Sound: A harsh chirping or clicking sound made whenever another male intrudes on his territory for eating and resting.

3. Fear and Defense

• The Message: "Go away from me!"
• The Sound: A sudden scream to scare the predator away.