Why Do Lizards Do That Throat Thing?

Lizards frequently display a vibrant flap of skin under their chin, often referred to as "that throat thing," which is actually a specialized structure known as a dewlap. This unique display is a critical form of communication, primarily used by male lizards for a variety of vital purposes, including attracting mates, defending territory, and deterring threats.

What is a Dewlap?

The dewlap is a colorful, often brightly patterned, retractable flap of skin located on a lizard's throat. When displayed, it is extended and flared out, creating a striking visual signal. While found in both sexes of some species, it is particularly prominent and frequently used by males, especially among Anolis lizards.

Key Reasons for Dewlap Displays

Lizards unfurl their dewlaps as a visual signal in various situations. The primary reasons behind this distinctive "throat thing" are:

1. Attracting Mates

For many lizard species, the dewlap serves as a crucial tool for courtship and attracting females.

• Vibrancy and Health: The brightness and size of a male's dewlap can signal his health, genetic quality, and fitness to potential mates. A more impressive display might indicate a stronger, more desirable partner.
• Species Recognition: The unique patterns and colors of the dewlap also help females identify males of their own species, preventing interbreeding.
• Courtship Rituals: Males often combine dewlap displays with head bobs and push-ups as part of elaborate courtship rituals to impress females.

2. Establishing and Defending Territory

Lizards, especially males, are often territorial, and the dewlap plays a significant role in repelling rivals and asserting dominance.

• Warning Signal: When a male lizard encounters another male, he will often flare his dewlap as a clear warning to "back off." This display can be a preliminary step to physical combat, aiming to avoid a direct fight.
• Dominance Display: A larger, more vibrant dewlap display can intimidate smaller or weaker rivals, establishing the displaying lizard's dominance within a particular area.
• Boundary Marking: Frequent dewlap displays around a territory's perimeter help to signal its occupancy to potential intruders.

3. Deterring Predators

While primarily for intraspecies communication, the dewlap display can also serve as a defense mechanism against predators.

• Startle Effect: The sudden, unexpected flash of a brightly colored dewlap can startle a potential predator, giving the lizard a critical moment to escape.
• Making Appear Larger: By extending the dewlap, a lizard can temporarily appear larger and more intimidating than it actually is, potentially discouraging a predator from attacking.
• Distraction: The rapid movement and color might draw a predator's attention away from the lizard's main body, allowing it to flee.

Summary of Dewlap Functions

The multi-functional nature of the dewlap makes it a fascinating example of visual communication in the animal kingdom.