The following are questions about the most conspicuous lizards native to the Southeast. Some people call them green anoles, others American chameleons.
Q. I live in northern Alabama and recently saw a dozen lizards (the chameleon-like ones that change from brown to green and back) in the yard. Is there some kind of food we could put out for them this winter? Also, do these lizards hibernate?
A. Yes, green anoles hibernate in colder regions of their geographic range, which extends from the Carolinas, throughout Georgia and Florida, to Alabama and on to east Texas. They often hibernate in large groups and were probably congregating before it turned cold. Anoles spend winter under bark, inside rotten logs, or under boards of houses and barns. They can be seen on bright, sunny days in winter basking in the sun. As for feeding them, they will do fine with no help from us as they eat little or nothing in winter. When spring arrives, they will feed on small insects and spiders around the yard.
Q. I have noticed that the lizards around our house in South Carolina are sometimes brown, or even gray, and sometimes brilliant green. I thought the lizards that changed colors were chameleons that mimicked the color of the object they were on. But I recently saw a green one sitting on a brown branch and on another day saw a brown one on some green vegetation. What gives?
A. Part of the confusion comes from green anoles being in a completely different family of lizards from Old World chameleons, which do change color based on their substrate and background, creating a true camouflage. The green anole’s brown-to-green-to-brown color change is not that simple. Color change in green anoles is a response to other environmental factors, such as temperature and humidity. It can also be influenced by their hormonal or emotional state. Being threatened by a predator, being challenged by another anole, or even increasing their level of activity can result in color changes. Most anoles hidden under bark or leaves in late fall and winter will be brown, whereas they usually turn green if they bask in the sun. However, scientists do not understand all the factors that make a green anole change color. Sounds like a worthwhile science fair project.
Q. We were wondering if the warmer winter we had in Georgia last year could explain the increase in the number of anoles we found around our house and yard last summer.
A. Warmer winters could possibly result in more insects for anoles to eat in the spring, which could lead to an increase in reproduction in the species, and therefore more lizards. However, determining the exact cause of an increase or decrease in the population numbers of animals is extremely complex, even for population ecologists who study a particular species in a prescribed area. Part of the problem is the difficulty in determining whether an observed effect (such as change in population size of the lizards) is the direct result of weather or climate changes that affect the animal itself or an indirect result of an effect on another species (such as a parasite or predator) that might influence population size. To further complicate matters, some changes in numbers of an animal species, even over a several-year period, may simply be coincidental with an observed environmental change that is unrelated to the species.
Q. Why do the anole lizards we see that can change from brown to green sometimes have a bright red throat?
A. Male anoles use a throat fan, or dewlap, to challenge other males, and sometimes even people. The dewlap is typically bright red in the native anole and yellow, orange, or a combination of colors in some of the introduced anoles now found in southern Florida. The display of the dewlap is often accompanied by the male lizard doing push-ups and bobbing its head. Next time you notice one with a red throat, hang around and see if he will put on a show.
Send environmental questions to firstname.lastname@example.org.
Whit Gibbons is an ecologist and environmental educator with the University of Georgia’s Savannah River Ecology Laboratory.