Many reptile species are very sight-oriented animals, relying heavily on vision to find food, evade predators and even communicate with each other. Iguanine lizards (infraorder Iguania, including the families Agamidae, Iguanidae and Chameleonidae), are particularly visual, displaying bright colours, elaborate body decorations and even behavioural demonstrations.
Giant Green Iguanas (Iguana iguana) have their own unique body language. Learning to interpret your iguana's body language can help you understand when he or she is pleased, uncomfortable, or giving you a good warning to be left alone! This is by no means a complete manual to iguana body language, which is quite complex when other iguanas are involved. This article will help you understand the body language that your iguana will display with you.
The Comfortable Iguana
Knowing how your iguana looks and acts while at ease will make it easier to tell when something changes. An alert, comfortable iguana is curious about its surroundings. It will walk about smoothly, occasionally stopping to tongue-flick the floor/ground or objects. Iguanas tongue-flick to gain more information about their surroundings by transferring particles to the vomeronasal, or Jacobson's, organ in the roof of the mouth. This is supposedly like a combination of taste and smell. Iguanas do smell their surroundings while they breathe through their nostrils, like we do, and tongue-flicking equates to a person sniffing an object to get a better sense of its nature. Iguanas will tongue-flick more frequently if they are in a new, non-threatening environment, or if something is different about a familiar environment.
A very comfortable iguana will lay down to rest by letting its chest lay flat, resting its arms against its sides with the palms facing the sky, and sprawling its hind legs out behind it. This position is called back-slapping, and owners will often see their iguanas bask or sleep in this position.
An interesting note is that iguanas will close their eyes according to how they feel. A very relaxed or sleepy iguana will close its eyelids from the bottom to the top. This differs from when the iguana is resting briefly or trying to ignore something (or someone), both eyelids will meet at the middle of the eye.
Head bobbing is a behaviour common to many iguanids and agamids, and consists of the head nodding up and down. Head bobs have many possible interpretations depending on the situation, but it seems iguanas will sometimes head bob just to say “hello,” or they may just be confident in advertising that they are the biggest, toughest lizard around at the moment. This is especially true for mature males, who tend to head bob much more frequently than other individuals. The “hello” head bob is rather relaxed. The up-and-down motion of the head has a bit of side-to-side movement, and the dewlap (the flap of skin on the throat) is not extended too rigidly so that it jiggles a bit during the head bobs. Iguanas may also head bob like this when annoyed, but their posture will be different.
The Annoyed Iguana
Compared to the comfortable iguana, the annoyed iguana's body will be more rigid. Its arms will tense up and it may extend its dewlap. If back-slapping, it will often raise their chest up and lean away from the annoyance, and even close the eye closest to what is bothering it (the two eyelids will meet at the middle). It may give the head bob described above as the “hello” head bob.
If the annoyance is physical, like if you are petting the iguana and it is not enjoying it, they may try to bat you away with a hand or foot.
The Defensive Iguana
An iguana on guard will try to make itself look as large as possible so that whatever is harassing it will think twice. An annoyed iguana may make the transition to a defensive posture if it continues to be provoked.
The iguana will “puff up” as much as possible by moving its body position so that its side faces the aggressor, fully extending the dewlap so that it is rigid, erecting the dorsal spines, raising itself as high off the ground as possible, and laterally compressing the body to appear larger. This display is called hatcheting. The iguana will ready its tail to whip, and usually does not hesitate to do so.
When the perceived threat does not leave, the iguana may resort to open-mouth hissing and tail lashing (which is quite painful from a large lizard) as the iguana tries to retreat while maintaining a sideways presentation. This is often called crab-walking, as the iguana looks similar to the sideways-walking animal.
Only when head bobbing, tail whipping and retreating do not work will the defensive iguana resort to biting. Iguana bites are painful and dangerous because of their razor sharp teeth, but the defensive iguana has given you plenty of warning before biting!
The Aggressive Iguana
The iguana on the attack is something to be wary of, and is particularly common with males during the breeding season. You might see a warning head bob to alert you that an attack is on the way, a more vigorous head bob with rapid side-to-side motions accompanying the up-and-down movement. The iguana will be stiff and raise itself high off the ground, dewlap extended, dorsal spines erect. It may crab-walk at first, but then approach head-on, sometimes even launching themselves, ready to bite.
With their razor-sharp teeth, iguanas can be quite dangerous. Handling an aggressive iguana is equally dangerous. The safest method is to just get out of the iguana's way. One technique that may be used for hormone-driven males during breeding season is to establish to the lizard that you are not a male to combat or a female to mate with. Melissa Kaplan (author of Iguanas for Dummies and Anapsid.org [http://www.anapsid.org]) suggests that while the iguana is making a charge at you, turn your body towards him, take a square stance with feet apart and arms at right angles, and make yourself look big. Another method from Richard Hatfield (author of Green Iguana: The Ultimate Owner's Manual) is to pick up the iguana in the middle of a charge, hold him at arms' length and eyes' height and firmly say “NO, NO, NO” (or some other phrase), then dump him onto the floor. Both methods try to get the point across that you are the “bigger lizard,” and may help discourage the iguana from bothering you with attacks.
There is no simple, concrete equation to iguana body language, but some things are dead certain cues as to how your iguana is feeling. Some of these behaviours may mix into each other a bit, and learning your iguana's particular personality is vital in establishing a good relationship with your pet.
