Anoles are insectivorous lizards, frequently seen in gardens and forests, as well as for sale in pet shops. Two species are found in the United States, the native green anole (Anolis carolinensis) and the introduced brown anole (Anolis sagrei). The two species are similar, sharing a recent ancestor, but have evolved different life strategies and morphologies over time.
Both varieties of anole are similar in overall body plan: they are somewhat stocky lizards with blocky heads, and long, lean legs and tails. Both have a dewlap under the chin, used in elaborate territorial displays, though it is usually pink in green anoles and dark red in brown anoles. Green anoles are generally patternless, while brown anoles frequently display dorsal stripes, spots or bars. Both lizard species possess color-changing capabilities, though brown anoles are always some shade of brown -- green anoles can display either brown or green colors. Brown anoles frequently have a dorsal crest, particularly in males.
Green anoles are the only species that is native to the United States, and can be found from Florida as far north as Tennessee and the Carolinas. By contrast, brown anoles are native to the Caribbean, with one subpecies being found in the Bahamas (Anolis sagrei ordinatus) and another in Cuba (Anolis sagrei sagrei). Representatives of both subspecies have been introduced to Florida and south Georgia, where they interbreed freely. Currently, the two subspecies of brown anole have integrated so thoroughly in south Florida that it's impossible to distinguish which island they originated from. Green and brown anoles interact where their ranges overlap; they're known to execute territorial displays aimed at the other species.
Some anole species are adapted to living in the crowns of trees, whereas others are adapted to living on the trunks; both have behaviors and physiology to reflect this. This combination of micro-habitat and body design is termed an ecomorph. The green anole is a member of the crown-trunk ecomorph, members of which are characterized by green body color, no enlarged dorsal scales and a tendency to climb up when in danger. The brown anole, by contrast, is a member of the trunk-ground ecomorph, whose members are usually brown, have enlarged dorsal scales and tend to flee toward the ground when threatened.
Though equipped with slightly different survival strategies, life histories and ecomorphs, both species of lizard share roughly similar ecology. Females of both species lay eggs singly throughout the summer. Anoles of all species are important predators of insects and arachnids. Birds and snakes are the most significant predators of anoles, though small anoles must be careful; both species are documented to eat the other.
- Savannah River Ecology Laboratory: Brown Anole (Anolis sagrei)
- Savannah River Ecology Laboratory: Green Anole (Anolis carolinensis)
- Florida Fish and Wildlife Conservation Commision: Non-natives - Brown Anole
- Anole Annals: Red In Beak And Talon: A Few Observations Of Birds Consuming Anoles In Urban South Florida
- Warnell School of Forestry and Natural Resources: Brown Anole (Anolis sagrei)
- Anoleannals.org: A Morning of Territorial Confrontations