Green Anoles are Area's Chameleons
Ro Wauer, August 3, 2003, The Victoria Advocate, © 2003
One of our most abundant lizards, the anole, is again abundant in my yard. It is almost as abundant now as it was four or five years ago. But after then my anole population began to decline, and within a couple years it was only a shadow of what it had been. And the population of scaly lizards, a species that was only seen occasionally, began to increase. By the next season they were the dominant lizard species in my yard. This of course does not include the ground skinks that seem always to be in good numbers among the leaves and debris in the yard.
Although scaly lizards are rather interesting lizards in there own right, my favorite is the anole. Scaly lizards are really shy and seldom permit a close inspection, but anoles often seem oblivious to a close approach. They often seem more curious than afraid at a close approach. I have even been able to get close enough to reach out and almost touch it before it moves away just far enough to feel safe. Then it will watch you as if wondering what you are really up to.
Our anole, more properly know as green anole, or Anolis carolinensis to scientists, is the only native anole found in our area. But there are 300 kinds worldwide. Except for the Key West anole of South Florida, all the rest occur in Mexico, Central and South America, and the West Indies. The green anole is a slender, long-tailed lizard, often as much as 7 inches in length. It has a long, pointed head and long legs and toes. The toes expand to form an adhesive pad for walking on slick surfaces. It can even walk up the surface of a glass window.
Territorial males often spread their conspicuous dewlap, or throat fan, as a territorial defense to warn an intruder or in courtship. This behavior is usually accompanied by a few bobs of the head or push-ups. If a rival male continues to trespass, a heated battle, with much biting, is possible. The resident male almost always is the victor and the intruder flees. The anole's dewlap contains a flexible rod or cartridge that is attached near the middle of the throat in such a way that it can be thrust forward by the attached muscles. When the fan is extended, the scales become widely separated, and a bright pink to orange color flashes into view.
The most fascinating feature of our green anole, however, is its ability to change color. For that reason it is often called "chameleon," after the Old World chameleon. This color change, resulting from changes in temperature, humidity, emotion, or exercise, can easily be seen as the anole moves from the shade into direct sunlight or from a dark to light object. Color changes can be striking and range from deep green to dark brown to light tan to blackish.
The color change is due to the arrangement of pigment cells in the anole's skin. When the cells expand, they partly cover other cells and produce the brown coloration, but when the black cells constrict to tiny dots, light is reflected from the other cells, giving it a green color. Cell movement is triggered by a tiny gland at the base of the brain that produces a hormone that controls the movements of the black cells. If the gland is removed, the animal remains pale green.
But no matter, the anole's neighborliness and curiosity, along with its abundance, are the characteristics that make it one of the most fascinating members of our native wildlife community.