Thursday, June 16, 2011

Invasive Species: Brown Anole

A male brown anole (Anolis sagreia) with dewlap extended

I first found out about the brown anole (small lizard native to the Caribbean) when I was in my Zoology class in 2008. At that point, none of the professors at my college, located in Southeastern Georgia had never seen one. They were something only seen in Florida, which has an ever-growing issue with invasives. Since then, they have become ever-more common, and earlier this year I did, in fact, see one on my college campus.

Invasive species are always dangerous because the true extent of their effect on a habitat will not reveal itself until the animal, or plant or whatever it may be, has been in the area for a significant period of time. Since these lizards have only been in Georgia for a short time, it is unclear what their presence will do to the native wild life.

Potential cause for alarm comes from the brown anole's relative, the green or Carolina anole (Anolis carolinensis, seen left). Since the brown anole's territory is expanding, more and more pressure will be placed on the greens, as their diets are quite similar. Also, and I have seen this first-hand during a trip to Florida, brown anoles will eat green anoles. In that same location, brown anoles clearly outnumbered green anoles. Even though this seems to imply that the browns are taking over, it is difficult to tell. It could just be that the greens are better able to blend in with their surroundings and thus were less easily observed. They are able to change from green to brown (the origin of their nickname "American chameleon") and are thus able to blend in very well. Or, it could in fact mean their numbers are dropping.

What does the future hold for these lizards? Will green anoles become extinct? Will the two species be able to coexist? Who knows. Unfortunately, we can only wait and see.

Images used are copyright-free from Wikimedia Commons


  1. I had several green or Carolina anoles as a child.

    I ordered a pair from Field and Stream, and they arrived in the mail from Texas. I had those for several years and then I caught my own in North Carolina.

    The brown anoles are bad news, but they are nothing like the European wall lizards that have been introduced to the Cincinnati area. The son of a wealthy department store magnate brought them back from Milan, where they took over parts of Ohio, Indiana, and Kentucky. They are larger than most native skinks and fence lizards and they are more aggressive toward them. The department store family's last name was Lazarus, and they are called "Lazarus lizards" in that part of the world.

  2. They are very popular pets. I've been catching them for years.

    Unfortunately that's a common story. Someone gets an exotic pet, then they don't want it any more and decided to let it go in their back yard. It couldn't hurt, right? Oh how wrong they are.

  3. European Wall Lizards have also been introduced to Victoria, B.C. on the west coast. So far it seems like they're only adept to urban life, however you know that phrase from Jurassic Park: "life will find a way."

    Brown Anoles, there is some interesting implication about the co-existence of Green and Brown Anoles. The Green are still just as common, however they took to the trees; while the Browns dominate the ground and lower branches. This is interesting because it has several evolutionary implications.

    The Cuban Knight Anole is the game-changer in Florida though since they are predatory lizard-eaters.