Why do lizards expand their throats?

The dewlap is a work of art.

If you have a male anole, you’ve probably already encountered it flaring its dewlap at you (or other lizards) multiple times.

If you have a female, she may flare it as well, but probably to a lesser extent.

This funny little orange-red pouch comes out at the most random times.

How can they inflate it like that? Do all anoles have it?

And why do they show it?

Let’s dive in and learn about these mysterious pink flaps of skin.

• What’s a dewlap?
• How does it work?
• What does the dewlap do? Why do anoles show their red throat?
  • Territory exhibition in male anoles
  • Dominance or defense
  • Mating
• Do all anoles have dewlaps?
• Do female brown anoles have dewlaps?
• All about dewlaps
• Further reading/references

What’s a dewlap?

A dewlap (“DOO-LAP”) is a non-verbal communication anatomical structure that lizards use to show dominance or get a mate.

Simply put, it’s a thin flap of skin that can be “inflated” right under the lizard’s neck. It’s also called a throat fan, a lizard blanket, or the “red or orange thing” under their neck.

Males have it, some females have it. It’s one of the sexual dimorphisms between a male vs. female anole. The size of it depends on the anole species, gender, and if the anole is a full grown adult.

How does it work?

The dewlap is inflated by a group of dedicated bones called the hyoid apparatus. It allows the anole to “blow” it up and release a large, circular flap that’s larger than its own head.

They can remain in this position for a few seconds while they bob their head, both of which are nonverbal communication between reptiles.

You’ll often see that the lizard doesn’t remain still while exhibiting the dewlap. It’ll be inflating and deflating it multiple times while bobbing its head.

The dewlap is red or orange in males and gray or white in females. Sunlight, UV, species, genetics, sex, age, location, or environmental effects can influence the overall appearance of it. This is why it’s sometimes red, pink, or orange. It can also be cream, white, or gray.

What does the dewlap do? Why do anoles show their red throat?

It’s used for a few different primary purposes:

• Establish territory dominance (males vs. other males)
• Defensive position
• Mating with a female

Territory exhibition in male anoles

For those that are unaware, males green anoles are territorial. They’ll defend their territory against other males that intrude.

One way to show their dominance is to flare their dewlap. This shows other lizards that a male has entered his territory and is in the danger zone.

From this point on, the two males may fight or the intruding male may leave and submit.

It’s a way of communication between anolis species to other creatures in the world. Males use them often and it can affect everything from mating to territory to their survival.

Females will rarely use them, and not all females have them. It’s said that larger dewlaps may increase the risk of predation, but also increase the chance of mating and securing a territorial location.

Males may also flare their dewlap to females, but this is rare. They often just let the female enter his domain and let her do what she wants.

Dominance or defense

If you’ve walked towards a stray anole, you may have seen him flare his dewlap at you

They also do this to anything they perceive as a threat so they can look more “scary” to their prey. They’ll inflate it against people, pets, dogs, cats, birds, and other reptiles.

Mating

As for mating purposes, the male will use it to bait female anoles. The larger and more colorful the dewlap, the higher quality of genes the male has- at least that’s what I’d assume.

This then brings in female attraction. It’s similar to how female lions like darker manes or female peacocks like larger and more lustrous male feathers. That kind of thing.

Do all anoles have dewlaps?

All male green anoles have dewlaps.

Females have them too, but they’re much smaller and they rarely use them. Not only anoles have dewlaps. Some iguanas, for instance, have them also.

However, the anole genius is most popular for the large dewlaps that can extend and retract. There are over 425 species total.

Some of the popular ones are the Cuban green anole, Allison’s anole, Bahamian green anole, Carolina green anole, Costa Rican anole, Bark anole, Crested anole, Equatorial anole, and the Knight anole. They all exhibit the dewlap.

The size, color, and shape of the dewlap vary by the anole species, sex, and environmental factors.

Do female brown anoles have dewlaps?

While all males have dewlaps, female anoles may also have them. They’re usually white or gray and a lot smaller in size.

Females will rarely display them, so it can be hard to determine if your lizard has one or not.

All about dewlaps

Now you know the basics about dewlaps in Anolis carolinensis. These beautiful, flappy pieces of throat skin are something to be marveled at.

Although you should never force your anole to defend itself or become stressed, when it does, you should take the time to enjoy it.

Avoid trying to handle it when the dewlap is out because it’ll probably bite you.

When you see two wild anoles outside, you now have a deeper understanding of what’s going on in their nonverbal communication.

Telling two males or a male and female should be easy just by looking at their dewlap.

Do you have any questions? Can this page be improved? Did you find it helpful or not? Leave a comment and let us know!

Further reading/references

• Evolution of Anolis Lizard Dewlap Diversity – PLOS
• Comparative tests of the role of dewlap size in Anolis lizard speciation – Royal Society
• Correlation between Anolis lizard dewlap phenotype and environmental variation indicates adaptive divergence of a signal important to sexual selection and species recognition – PubMed