Licking behaviour in Bearded dragons

Licking behaviour is frequently seen in Bearded dragons. Unlike, for example, Chameleons, Bearded dragons do not have long, projectile tongues to catch prey from a distance, but they do use them in similar ways.

Like any other reptile, Bearded dragons have a tongue that can be extended from the mouth. When looking closer, the tongue is short but stocky and can be extended about a quarter to half of the head’s length from the mouth. If you’ve ever been licked by a Bearded dragon, you would have felt that the tongue is slightly sticky and has a slight fork at the tip. Although not the only reason for using the tongue (see below), the stickiness of the tongue aids in the catch of prey and guidance of food into the mouth. In a healthy Bearded dragon, the tongue should be a light pink, often tinted towards yellow (the natural pigment of the Bearded dragon itself).

Adult Bearded dragon licking a pear. Image Multiphrenic (CC BY-SA 3.0)

Apart from using the tongue to catch prey, licking behaviour is actually an additional way for Bearded dragons to smell or taste. They also don’t lick things per se, but rather flick their tongues into the air at frequent intervals before retracting them back into their mouths.

By licking, Bearded dragons are actually ‘smelling’ and ‘tasting’ their environments. This enables Bearded dragons to get a better understanding of their environment during hunting, hiding, mate-seeking and breeding.

Jacobson’s organ

After each ‘lick’, microscopic particles from the environment collects on the surface of the Bearded dragon’s tongue. After the tongue is pulled back into the mouth it is pushed into an opening on the upper part of the mouth. This opening is connected to a sensory part called the Jacobson’s organ or the vomeronasal organ (not to confused with the pineal gland, which helps regulate photoperiod behaviours). By pushing the tongue onto the Jacobson’s organ, the particles from the environment can be deciphered into messages (similar to the taste buds and the inside of human noses). These messages are then transmitted from the Jacobson’s organ via nerves to the brain of the Bearded dragon. After the information has been received from the Jacobson’s organ, the brain make the reptile ‘understand’ its environment better.

This image shows the Jacobson’s organ of a snake, which is very similar in reptiles including Bearded dragons. Image credit Fred the Oyster (CC BY-SA 4.0)

Using the tongue to be able to ‘smell’ and ‘taste’ is not unique to Bearded dragons. Most other reptiles and many other animals also has this ability. Compared with other animals, Lizards, including Bearded dragons, have a well developed Jacobson’s organ.

Apart from being a sensing organ, it is also believed that in many animals the vomeronasal organ is responsible for detecting pheromones, aiding in reproduction and social behaviour. During the mating season and breeding, Bearded dragons might be seen flicking their tongues frequently.