How Fast Is a Chameleon's Tongue? Ballistic Hunting Explained

How fast is a chameleon’s tongue?

Researchers measure tongue strikes with high-speed cameras filming hundreds or thousands of frames per second. In larger chameleons, the tongue accelerates at more than 400 m/s² (about 41 g) and can hit an insect in under a tenth of a second. For comparison, a fast sports car accelerates at less than 1 g.

The record holders are the smallest species. In a 2016 study of about 20 chameleon species, the biologist Christopher Anderson found that the tiny Rhampholeon spinosus, a pygmy chameleon from Tanzania, launched its tongue with a peak acceleration of about 2,590 m/s², or 264 g. Its tongue produced a peak power of about 14,000 watts per kilogram of tongue muscle, far beyond what any muscle can deliver directly.

Body length here means snout to vent, without the tail.

How long is a chameleon’s tongue?

Textbooks often say a chameleon’s tongue is one and a half to two times the length of its body, and that holds for the large species that were studied first. Small chameleons turned out to be different. Both small species and small individuals have relatively bigger tongue machinery, so they can shoot their tongues farther for their size, more than twice their body length in some cases.

This makes sense ecologically. Small chameleons eat small, fast insects and need a long reach and high acceleration to catch them before they escape.

How does the tongue shoot out?

The secret is stored elastic energy. The tongue sits on a long, rod-shaped bone called the entoglossal process, part of the hyoid apparatus in the throat. Wrapped around this rod is a tube of muscle called the accelerator muscle, and between the two are layers of nested sheaths made of collagen, the same springy protein found in tendons.

Before a strike, the accelerator muscle contracts and squeezes the collagen sheaths, stretching them like a coiled spring. This loading takes a fraction of a second, while the tongue is still held in place. When it is released, the sheaths recoil all at once and the tongue slides forward off the tapered tip of the rod, a bit like a wet bar of soap squeezed out of a fist.

Because the energy is stored slowly and released almost instantly, the strike is far more powerful than muscle contraction alone could make it. Dutch researchers found evidence for this elastic mechanism in 2004, and later work confirmed that elastic recoil powers most of the strike.

The chameleon aims first. It turns its head, locks both turret eyes on the target and judges the distance; see how chameleon eyes work for the details.

How does the tongue catch and hold prey?

The tip of the tongue is a club-shaped pad. As it hits, it can bunch up into a cup that wraps around the prey and may create a little suction. It is also coated with very thick, sticky mucus. A 2016 study estimated that this mucus is roughly 400 times more viscous than human saliva, which helps explain how chameleons can hold surprisingly large prey.

Pulling the tongue back is a separate job done by the hyoglossus, a retractor muscle that lies pleated and bunched inside the mouth before the strike. Retraction is much slower than launch, but by then the prey is already stuck to the tip.

Do chameleon tongues work in the cold?

Yes, and that is one of the great advantages of the catapult. Reptiles depend on outside heat, and most of their muscles become slow in the cold. In a 2010 study using veiled chameleons, Anderson and Stephen Deban found that tongue launch lost very little performance when body temperature dropped, because it is powered mainly by elastic recoil rather than by fast muscle contraction. Tongue retraction, which is powered by muscle alone, slowed down markedly.

This means a chameleon can feed on cool mornings, before it has warmed up in the sun and while other lizards are still sluggish.

Is the chameleon tongue the fastest in nature?

It is among the fastest movements made by any reptile, but not the only extreme tongue. Some lungless salamanders also shoot their tongues ballistically using elastic energy, and certain species produce even higher power output. Woodpeckers have very long tongues too, but they work in a different way; see how long a woodpecker’s tongue is.

Among chameleons, the tongue is used by every species, from the large veiled chameleon of Arabia to the colorful panther chameleon of Madagascar and tiny leaf chameleons, which shows how central it is to their way of hunting. A chameleon cannot run down prey. Instead, it waits motionless, lets its eyes do the searching and fires its tongue, which turns a slow-moving lizard into an efficient ambush hunter.