BACKYARD BIODIVERSITY: Green Anoles

With more time than usual at our homes, and the weather not searing hot yet, it’s a great opportunity to get outside and become familiar with the species we have in our own backyards! The Green Anole (Anolis carolinensis) is a common lizard not difficult to spot if you have some greenery outside. They prefer moist environments near trees and shrubs, but they can also be found on fences and walls.

Males are slightly larger than females, and their tails can make up about 60-70% of their body weight. Males also have the distinct dewlap (a throat fan) that is bright red and larger than that of the female. The dewlap on females it is smaller and whitish in color. Females also have a white dorsal stripe that males typically lack.

One of the Green Anoles most fascinating traits is how they can change color. They can be bright green one moment and then turn dark brown the next. They do this with their three layers of pigment cells, one layer for yellow, one layer for blue, and one for brown. Anoles change color for a variety of reasons, such as when they are sending a social signal to another anole (to show dominance, for example), or as a reaction to stress or activity. During fighting, male anoles will develop black coloration behind their eyes. Sometimes, if an anole is beneath a strong shadow, the shadow will have a “stencil effect” and leave a temporary shadow on the anole’s skin. However, anoles do not change color according to whatever they are sitting on. They have, in fact, wrongly been called chameleons when their color-changing abilities are not as sophisticated as those of the true chameleon.

The absence of any one of the three color pigments is a mutation, and can cause some specimens to display colors like blue. Unfortunately, blue anoles have a harder time surviving in the wild as the blue makes it more difficult for them to hide from predators or to hunt down prey.

Another interesting trait about anoles is the mating “dance” the males do. During mating season, males defend their territory from other males. They will bob up and down while flaring their dewlaps in and out.

Anoles eat mostly small insects like grasshoppers, flies, and spiders. When they themselves become an intended food source, they can display caudal autonomy, meaning, their tails can break off and wiggle. This distracts the predator and allows the anole to get away to safety. The anole will grow back another tail, but this tail is not usually the same length as the tail it has replaced, and it contains cartilage rather than bone.

Thanks to Dr. Travis Laduc of the Herpetology Collection for his edits.

SOURCES

Brown, Linda. Green Anole: Beneficials in the Garden. 2004. Texas Master Gardener. (accessed online: https://aggie-horticulture.tamu.edu/galveston/beneficials/beneficial-19_lizard_green_anole.htm)

Green Anole (Anolis carolinensis). Texas Parks and Wildlife. (accessed online: https://tpwd.texas.gov/huntwild/wild/species/anole/)

Green Anole (Anolis carolinensis). Savannah River Ecology Laboratory, University of Georgia. (accessed online: https://srelherp.uga.edu/lizards/anocar.htm)