These male lizards glow to get the ladies
This is how bachelor Jamaican Gray lizards show off in shady forests.
He-men of the Homo sapiens species have their tricks to woo the women … flashy cars, gym-built physiques, questionable colognes. But males of the Anolis lineatopus have them beat thanks to their throbbing glowing throat pouch.
While the researchers studying anoles don’t exactly call it a “throbbing glowing throat pouch,” they have discovered that male anoles do indeed have a unique method for attracting attention. They bob their heads up and down to extend a colorful throat fan, called a dewlap. In shaded habitats, the dewlap is frequently translucent; with light passing through it from the back, it glows. The dramatic effect, according to a new study published in Functional Ecology, increases the efficacy of the male lizard's visual signal, making them stand out better to females.
"When I first saw this glowing effect in the field, I thought, 'Wow! There is something special about this,'" said Manuel Leal, a biologist at the University of Missouri who coauthored the study.
Lizards in shaded habitats have to compete with the "visually noise" of their environment, especially with trees and plants moving in the wind. Leal and his team postulated that this glowing effect makes the lizard's visual signal easier to notice by either making the dewlap appear brighter or making the colors more evident against the background.
"When lizards are displaying amongst trees, where the background is shaded, a feature like this actually makes a lot of sense," said Leal.
To test their hypothesis, they studied Jamaican Gray lizards, (A. lineatopus) and found that when light is transmitted through the dewlap, perceptual overlap is decreased.
"Allowing light to pass through the dewlap makes the colors of the dewlap much easier to detect and to distinguish against other objects in the background, which means the signal is easier to see by potential mates and rivals," explained Leal. "In other words, it increased the signal-to-noise ratio."
Although translucent coloration is known throughout the animal kingdom, its purpose and underlying mechanism is not well understood. According to the authors, "this is the first study to demonstrate the evolutionary advantage of possessing a translucent display organ that uses diffuse transmitted light to increase its visibility."
You can see the action in the video below. It really is an incredible way to attract attention ... no Ferrari required.