If you’ve ever seen a lizard in the wild or kept one as a pet, you’ve likely noticed their curious habit of sticking out their tongues. This strange behavior might seem random at first glance, but it actually serves several important purposes for these reptiles.
In this comprehensive guide, we’ll explore the fascinating reasons why lizards stick their tongues out and what they’re able to sense with this unique organ.
In short, lizards stick their tongues out to smell and sense their environment. Their tongues act like chemical receptors, picking up scents and pheromones from the air and ground. This helps lizards hunt prey, avoid predators, communicate, and navigate their habitats.
Tongue Structure and Jacobson’s Organ
Forked shape allows lizards to detect chemical cues
One of the most iconic features of lizards is their long, forked tongues. The unique structure of a lizard’s tongue allows it to effectively gather chemical information from the environment. When fully extended, the two tips of the tongue can cover a large surface area, maximizing the detection of scents and pheromones.
The forked shape also allows the tongue to pick up scent particles from two different directions at the same time, helping the lizard hone in on the location of food, predators or potential mates. This evolutionary adaptation helps lizards survive and thrive in their habitats by enhancing their sensory abilities.
Contains Jacobson’s organ for detecting scents
Inside a lizard’s mouth is an important scent detection organ called the Jacobson’s organ. When a lizard sticks out its tongue, it picks up microscopic chemical particles from the air or ground. These particles stick to the mucus coating the tongue and are transferred to two ducts leading back to the Jacobson’s organ.
Here, receptor cells analyze the scent molecules, sending signals to the brain so the lizard can interpret them. This organ gives lizards their remarkable sense of smell and taste, which is essential for finding food, identifying predators and social communication.
Essential for gathering sensory information
A lizard’s forked tongue and Jacobson’s organ work together to provide key sensory information about the surrounding environment. Constant tongue flicking and scent analysis allows lizards to continuously monitor their habitat for the subtle chemical signals that could mean the difference between life and death.
According to research from the Max Planck Institute, some lizards may flick their tongues up to 60 times per minute while foraging and exploring their territory. Without this unique physiological adaptation, lizards would lack the sensory advantage they need to react quickly to threats and opportunities.
Hunting and Foraging
A lizard’s forked tongue plays a critical role in helping it locate food. As ambush predators, lizards rely heavily on their sense of smell to track prey. When a lizard flicks its tongue out, it picks up scent particles from the air and ground.
These scents stick to the twin tips of the tongue, which has specialized cells for detecting chemicals. As the National Geographic explains, “a lizard’s tongue is a sensory organ.”
Tongue picks up scent trails left by prey
When the lizard retracts its tongue, the tips transfer the sampled scent particles to the vomeronasal organ, also called Jacobson’s organ. This sensory structure sits in the lizard’s mouth roof and contains receptors that analyze these scents.
So a lizard’s forked tongue allows it to gather a stereo-like chemical image of its surroundings (Ask a Biologist). This unique ability means a lizard can follow scent trails left behind by passing prey.
Guides lizards to food sources like insects or small animals
These scent cues guide lizards to promising food sources, like anthills teeming with ants or rodent burrows filled with young mice. In fact, Varanus lizard species can even use their forked tongues to track seabird eggs buried deep beneath the sand.
Researchers found the Varanus rosenbergi species could dig up 90% of buried eggs based solely on scent clues, an impressive feat (Science Daily). So a lizard’s wiggling tongue allows it to literally “sniff out” prey animals that would otherwise remain hidden from view.
Especially useful for ambush predators lying in wait
A forked tongue is especially beneficial for ambush predators that spend long periods lying perfectly still, waiting to launch an attack. Over 75% of all lizard species fall into the “sit-and-wait” predator category (American Museum of Natural History).
With a quick tongue flick, these lizards can sample the area for signs of approaching prey without giving up their camouflaged position. Researchers found the Savannah monitor lizard Varanus exanthematicus uses its forked tongue to detect prey up to 30 feet (9 m) away (Science Daily).
So a still-hunting lizard essentially has built-in “prey radar” thanks to its wiggly tongue.
In short, a lizard uses its forked tongue to collect scent samples from the environment. These chemical clues then guide the reptile to promising food sources, even hidden or buried prey. So that wiggling tongue allows lizards to survive as skilled predators in diverse habitats worldwide.
Avoiding Predators
Senses chemical cues from potential threats
A lizard’s tongue is a vital asset for detecting danger before it strikes (National Geographic). Their tongues have specialized sensory cells called chemoreceptors that pick up scents and pheromones in the air.
When a lizard flicks its forked tongue out, it gathers chemical particles and transfers them to a sensory organ in the roof of its mouth called the vomeronasal or Jacobson’s organ.
This highly developed sense of “smell” allows lizards to be aware of predators like snakes, mammals, and birds in their surroundings even if they can’t see them. For example, if a snake is nearby, the lizard may detect traces of its skin chemicals and decide to flee before becoming its next meal!
Gives lizards chance to flee or hide from danger
By detecting threats early, sticking out their tongues provides lizards valuable time to escape or hide (HowStuffWorks). Some species like the common side-blotched lizard (Uta stansburiana) rely on camouflage and speed to avoid predators.
When they sense a nearby coyote, hawk, or rattlesnake, they quickly scurry under a rock crevice or bush to disappear from sight.
Other lizards like chameleons and anoles use more stationary means of escape. After peeking at their surroundings with a tongue-flick, they may compress their bodies to appear twig-like or gradually change color to match their background. This helps them vanish before a dangerous foe discovers them.
May pick up scents from snakes, birds, mammals etc.
Various predatory species trigger lizards’ tongues to shoot out and assess threats, including:
- Snakes – often compete for habitats and food sources
- Birds – especially hawks, falcons, and roadrunners that hunt lizards
- Mammals – such as foxes, bobcats, raccoons, coatis
- Other lizards – large dominant species may see small lizards as prey
In one study, researchers found the tongues of Sceloporus lizards flicked out 17 times more often when predatory odors from snakes and mammals were introduced. So when lizards rapidly tongue-flick, its likely danger isn’t far away!
Communication
Picks up pheromones and scent markings from other lizards
A lizard’s tongue is a critical tool for communication. When a lizard flicks its tongue out, it picks up tiny chemical particles called pheromones from other lizards and from scent markings in the environment.
These pheromones provide a wealth of information including the sex, reproductive status, health, territory ownership and social status of nearby lizards.
Lizards actually have a special sensory organ called the vomeronasal or Jacobson’s organ that is dedicated to detecting and analyzing these chemical signals. As a lizard flicks its tongue out, it sticks the tips to surfaces and then quickly retracts its tongue to transfer the collected pheromones to the Jacobson’s organ.
This allows lizards to constantly monitor social cues and updates in their environment by frequently sampling the air and various marked locations.
Indicates territories, social status, and readiness to mate
By flicking their tongues out frequently, male lizards can advertise their dominance, virility and territory ownership to competing males and receptive females. The pheromones in their scent markings convey important information about their size, strength, health and social position in the hierarchy.
For females, tongue flicking helps identify optimal mates and assess their readiness to breed based on chemical signals. Females also mark territories with pheromones and will tongue flick to find areas marked by high status or genetically suitable males.
By picking up on reproductive chemical cues, both males and females can coordinate their mating behaviors and rituals more effectively.
Essential for reproductive behaviors and rituals
Scent cues detected through tongue flicking are essential triggers for key reproductive behaviors in lizards. For example, male lizards often engage in a stereotypical courtship ritual of head-bobs and pushups upon smelling female pheromones signaling fertility.
Some lizards also use their tongues during copulation to transfer pheromones that influence female receptivity, ovulation timing and offspring viability.
Additionally, pregnant female lizards may frequently tongue flick to identify optimal egg-laying sites marked by chemical cues from other females. Overall, the unique chemical communication enabled by tongue flicking allows lizards to successfully coordinate their breeding cycles for effective reproduction.
Navigation
A lizard’s tongue serves an important navigational function. This unusual appendage guides lizards toward critical resources like food, water, safety, and potential mates in several key ways:
Guides lizards toward safety, food, mates, and water
A lizard’s forked tongue is a sensitive chemosensory organ, allowing it to detect chemicals in the air to locate prey and identify predators. By flicking its tongue out, ions in the air stick to the tongue, which the lizard then brings back into its mouth.
Sensory cells analyze these captured molecules, informing the reptile if food, threats, or mates are nearby.
For instance, the tongue helps locating tasty insects to eat. It also sniffs out the pheromones of potential mates during breeding season. Furthermore, lizards can sense the scent trails of predators, steering clear of danger.
Helps orient themselves in complex environments
In complex terrain like forests and deserts, lizards utilize their tongue to build spatial maps and navigate obstacles. Researchers found the Texas spiny lizard’s tongue guides it through dense brush. As it moves, it constructs a mental model of its surroundings, avoiding hazards.
This function explains why climber lizards, like geckos and chameleons living in trees, shrubbery, and rock piles, stick out their tongues so frequently. These environments are intricate 3D puzzles, and the tongue assists plotting efficient routes.
Especially useful for climbing lizards navigating trees/rocks
Arboreal lizards often have specially adapted tongue tips allowing them to map complex branches and crevices. For instance, chameleons have ball tips, while Texas spiny lizards feature elaborate horned forks.
These features allow maximum surface contact, with the horns and balls fitting into nooks to extract environmental data.
| Lizard Type | Tongue Adaptation | Terrain |
|---|---|---|
| Chameleon | Ball tip | Tree branches |
| Texas Spiny Lizard | Forked with horns | Dense brush |
Studies revealed how a gecko’s brain constructs detailed 3D maps from tongue data to master rugged habitat. Without this input, it struggled moving through its home terrain. Truly, for climbing species navigating forests and jumbles of rocks, the tongue is an indispensable navigation instrument!
Conclusion
In summary, lizards stick out their forked tongues to collect sensory information about their surroundings. This unique organ aids essential behaviors like hunting, avoiding threats, communicating, and navigation.
The next time you see a lizard tongue flicking in and out, you’ll understand the importance of this peculiar reptilian habit.
