The green anole is no chameleon, but its colour still tells a story
People across the American South call the green anole a chameleon, yet it is closer kin to iguanas. Its ancestors rafted from Cuba to the mainland millions of years ago, an unusual case of an island species conquering a continent, and today it flashes a pink throat fan to warn rivals away.
This slim tree lizard reaches 12.5 to 20.3 cm, and most of that is tail. Sticky toe pads help it climb, and it moves mainly by jumping. It shifts from bright green to dark brown using three layers of pigment cells, yellow, blue and brown-black, and the change tracks mood, stress, activity and social signals rather than the background, despite popular belief. Males turn greener when advertising territory. Standing in sharp shade while changing colour can leave a temporary stencil of the shadow on its skin, and in a fight dark spots may appear just behind the eyes.
Missing pigment genes produce rare colour phases. An anole without yellow pigment cells looks pastel blue, a variant seen about once in 20,000 wild individuals and prized in the pet trade, while one lacking blue cells looks yellow. Neither usually lasts long in the wild, since green is its camouflage.
Males are fiercely territorial, sometimes attacking their own reflections in windows. Facing a rival, a male flattens his body, extends a throat fan three times the size of a female's, raises a crest and bobs his head; bigger fans go with stronger bites. Lizards may see further into the ultraviolet than people, and the fan may reflect UV to impress mates.
Native from Virginia to Texas, the species copes well with cities such as Atlanta, turning up on railings and porches. Introduced populations have spread to Hawaii, the Canary Islands and Japan's Ogasawara Islands, which listed it as invasive in 2005 after insect numbers collapsed. At home it faces competition from the brown anole, which arrived in the early 1900s and pushed it higher into the trees, while in southern Florida it interbreeds with the introduced Cuban green anole. A 2022 study found some of those Cuban genes linked to urban conditions.
Source: Anolis carolinensis
