Reptiles
Green Anole
Anolis carolinensis · also called Carolina anole, American anole, American chameleon
The green anole is the small lizard doing push-ups on a fence rail across the American South, flashing a pink throat fan at rivals. Pet shops call it the “American chameleon” — which it is not — and in much of its range it is quietly being displaced upward into the trees by a Caribbean cousin.
Overview
Anolis carolinensis lives across the southeastern United States, in woodland edges, gardens, and swamp margins. It is 12–20 cm long, slender, and mostly tail. It changes between bright green and brown within minutes, controlled by hormones, temperature, and stress — not by background-matching.
The throat fan
Males stake territory and court by flicking out a pink-red dewlap, a fan stiffened by cartilage, while bobbing and doing push-ups. Sticky toe pads let them sprint up glass; a seized tail breaks off and regrows.
Character displacement
Since the brown anole invaded from Cuba and the Bahamas, green anoles have moved higher into vegetation, and within about 20 generations evolved larger toe pads for gripping thin twigs — a textbook case of two species dividing a habitat and of evolution seen in real time.
In the lab
In 2011 the green anole became the first reptile other than a bird to have its genome fully sequenced.
Status
The green anole is Least Concern and stable, common in gardens and parks even where brown anoles are dense.
Green Anole: common questions
Is the green anole a chameleon?
No. It is often sold as an American chameleon because it can turn from green to brown, but it belongs to a completely different group, the anoles, which are relatives of iguanas and native to the Americas. True chameleons are an Old World family with turret eyes, a ballistic tongue, grasping feet, and colour change driven largely by mood and signalling. The green anole's colour change is simpler and more limited, running between green and brown, and is influenced by temperature, light, hormones, and stress rather than by an attempt to blend into whatever it is sitting on.
What does it mean when a green anole turns brown?
Brown is generally the colour of a cool, stressed, or subordinate anole, and green the colour of a warm, calm, active one, though it is not a hard rule. A lizard that has just been chased, handled, or beaten in a territorial dispute often goes dark brown, and one basking contentedly in the morning sun is usually bright green. Persistent brown colouration in a captive animal, especially with dark patches behind the eyes, is a sign that something is wrong, commonly temperatures that are too low, an enclosure that is too small or too exposed, or social stress from being housed with a dominant male.
Why are green anoles disappearing from some yards?
Because of the brown anole, Anolis sagrei, a stockier ground-favouring species from Cuba and the Bahamas that has spread explosively through Florida and the Gulf Coast since the mid-twentieth century. Where brown anoles become abundant, green anoles are seen far less often at ground and fence level. They have not vanished; studies show they move upward into the shrubs and tree canopy, partitioning the habitat, and populations persist there. It is one of the clearest real-world examples of two similar species dividing up a shared environment, and of rapid evolution, since the shifted green anoles quickly developed larger, grippier toe pads.
Do green anoles make good pets?
They are inexpensive and widely available, but they are better as an animal to observe than to handle. They are fast, easily stressed, and drop their tails readily, and they need a planted vertical enclosure with climbing branches, UVB lighting, a warm basking spot, daily misting for drinking, and a steady supply of small live insects. Many sold in shops are wild-caught and arrive in poor condition. A small group of one male and a few females in a large, well-furnished tank does best; two males will fight.