March 19 – My Nature Journal

Green Anole

Anolis carolinensis

A Misleading Name For A Color-changing Lizard

Green Anoles are well–named most of the time. But the name can be misleading because Green Anoles aren’t always green. They can change the color of their skin in response to environmental conditions.

Green Anoles turn a vibrant, light emerald green in bright light, and when the lizards rest amongst or against green foliage. But in dim light, or damp, cool conditions, their skin darkens to a dull brown.

The change happens in a mere second or two and is fascinating to watch. An individual lizard can be bright green one moment, skitter into dead leaves on the forest floor, and become completely invisible the next as its skin fades to match its new surroundings.

Green Anoles are the only lizard in North America with this special, color-changing talent.

Putting On A Show For The Lady Lizards

Today’s Green Anole perched on a wide, metal bridge railing. Because the railing is a dark color, the lizard was brown, rather than green. He held his ground as I photographed him from several yards away, clearly focused on more important things.

Green Anoles mate in the spring. During mating season, male lizards perform a particular visual display to communicate territorial ownership and physical fitness to other Green Anoles in the area.

Both sexes of Green Anoles have a pad of thin, stretchy skin beneath their lower jaws called a “throat fan”, or a “dewlap”. But the males’ throat fans are much larger and stretchier than those of the females.

At rest, Green Anoles hold their throat fans folded invisibly along their throats and lower jaw. But during mating season, adult male Green Anoles inflate their throat fans, which stretch into conspicuous, knobby, bright pink balloons.

Male Green Anoles spend a lot of time during the mating season engaged in two activities: attracting females with whom to mate and competing with other males.

Throat fan posturing communicates strength, physical fitness, and territorial ownership to both groups of fellow lizards. Male Green Anoles with larger, more colorful throat fans—and those with the stamina to continue inflating them for extended periods of time—win more dominance competitions and more females.

So this guy was engaged in some serious work. I snapped my photographs and gave him a wide berth so as not to disturb him.

And as I walked away, I wished him well in his quest to entice some lady lizards to his side.