Click:The Green Anole (Anolis carolinensis carolinensis) in the Wild and Captivity; – Natural History – Part 1 to read the first part of this article.
Introduced Anoles
The green anole is the only anole native to the USA, but eight other species, originating as escaped or released pets, have established breeding populations here. The most common and widespread is the brown anole (A. sagrei), now found throughout Florida and in southern Georgia, Alabama, Louisiana, Texas and Hawaii. In many areas it is now more commonly encountered than the green anole.
The knight anole (A. equestris), bark anole (A. distichus), large-headed anole (A. cybotes), Hispaniolan anole (A. chlorocyanus), Cuban green anole (A. porcatus) and Jamaican giant anole (A. gormani) are limited to the vicinity of Miami and Miami-Dade County at this time.
Ill Fated Pets
Green anoles were sold by the millions at carnivals, circuses and through the mail in the 1960’s and early 70’s. Termed “chameleons” due to their color changing abilities, most were fed “sugar water” and expired in short order.
Color Change – not as obvious as it seems
Color change in the green anole has little to do with the background upon which the animal rests (although the colors it exhibits are usually cryptic). Cool or stressed anoles are brown in color, while warm, resting individuals are pale green and warm, active animals are bright green. Anoles involved in aggressive displays develop a black patch behind the eyes.
Unique Climbing Aids
Green anoles are assisted in climbing by transverse lamellae on the bottoms of the toes and feet. These thin structures are divided by thousands of grooves, and provide excellent traction against tiny irregularities in the surface upon which the lizard is moving. Utilizing the lamellae, anoles can even grip dirt particles lodged on glass, and hence climb window panes and aquarium sides easily.
Cold Tolerance and its Conservation Implications
Research has demonstrated that anoles from south Florida lack the cold tolerance exhibited by those in north Florida, and could not survive the winters there. Information such as this is vital in planning reintroduction and captive breeding programs for animals with large ranges. Inter-breeding animals that originate in widely different parts of their range can have disastrous consequences, despite the fact that they are of the same species.
In one case, ibex (mountain dwelling goats) from several European countries were released in the Pyrenees Mountains, to bolster the local population. The animals reproduced, but the offspring resulting from the crossing of native and non-native ibex were genetically programmed to give birth in mid-winter, and the population eventually became extinct.
An interesting summary of research being conducted on free-living green anoles by students at UT Knoxville is posted at:
http://eeb.bio.utk.edu/echternacht.asp