The Chameleon is widely recognised by most people, often most well known for its colour changing ability. Amazingly, there are over 200 species of Chameleon in the world, with a massive 38% of these species being found in Madagascar alone. The remaining 62% are predominantly found in sub-saharan Africa, but some species can be found in southern Europe, the middle east, India, Pakistan, Sri Lanka and nearby islands. But in their mouths these fascinating reptiles hold an amazing secret weapon!

What do Chameleons eat?

The main food source of a Chameleon is live insects and invertebrates such as worms, crickets, and flies. Larger Chameleon species have been known to prey on other small reptiles and birds in the wild. The common point to note is that the vast majority of a Chameleon’s diet is live food, which is why their tongue is such an important part of their anatomy and critical to ensuring they can catch their prey, and ultimately ensure their survival. 

What is special about the Chameleon tongue?

1) Chameleons are able to extend their tongue to two and a half times their body length. This is equivalent to a six foot human having a fifteen foot tongue!

2) Chameleons can extend their tongues extremely quickly, with some species completing tongue projection in as little as 10ms (also known as one hundredth of a second or 0.01 seconds). To put that in perspective, the human blink takes on average 100-150ms, or 0.1-0.15s, so you wouldn’t just blink and miss it, you would blink and miss it 10 to 15 times over!

3) In order to capture their prey, Chameleons have specially adapted mucus on their tongues that is extremely sticky, which ensures their prey sticks to the tongue and can be pulled back into their mouth.

How does the Chameleon tongue work?

The Chameleon’s tongue is described as having ‘ballistic projection’ and it is often referred to as a ballistic tongue. The Chameleon’s muscles control the tongue but rely on energy stores within the cells of the tongue to project the tongue out of their mouth at such extreme speeds. The energy from the tongue’s cells is released rapidly when the muscles initiate tongue projection, which results in the incredibly fast prey capture. The tongue sits on a bone in the Chameleons mouth known as the entoglossal process. This bone structure effectively works as a launch pad for the tongue enabling it to use the stored energy to project out of the mouth. 

Interestingly, the tongue is withdrawn at much lower speeds than it is projected, and this is controlled entirely by normal muscle contraction as with our own tongues. It therefore does not require any additional energy stores, unlike the projection process. When we consider the function of the tongue projection is to catch live prey, it makes sense that there is little need to recoil the tongue as fast, as it’s important for the Chameleon to ensure they have captured their prey and it is stuck to the mucous properly before they bring it into their mouths. That being said, the whole process from tongue projection to capture of prey, recoiling of the tongue and the Chameleon starting its meal is still over in less than half a second! 

You can read more about the Chameleon tongue in this fascinating article from the Royal Society.

Are there other species with a tongue like the Chameleon?

Chameleons are the only living species known to have a ballistic tongue. However, palaeontologists have discovered fossil evidence in Myanmar, South East Asia, that 99 million years ago an extinct species, known as an albanerpetontid, also had a ballistic tongue. This tiny amphibian lived many years before the Chameleon, however recent remains found preserved in amber showed evidence of the same entoglossal process (bone) that Chameleons have in their mouth which enables the projection of the tongue – fascinating!

You can read more about this discovery from the Smithsonian.

Summary:

  • Chameleons have a ballistic tongue which they can project out of their mouth in 1/100th of a second!
  • Chameleons tongues are covered in a sticky mucous that allows them to capture their prey
  • Chameleons are the only living species known to have a ballistic tongue