Anoles

A competition for shelter and food is raging across Florida, and two related lizard species have been adapting to the presence of each other for decades.

Florida’s native green anoles (pronounced “uh-noles”), Anolis carolinensis, found themselves in competition with the Cuban brown anoles (Anolis sagrei) over a century ago. Native to Cuba, the Bahamas, and the Cayman Islands, Cuban brown anoles are now the most common lizard in many urbanized parts of Florida.

The decline in green anoles may not be wholly caused by competition, but it is due in large part to the presence of the introduced Cuban brown anoles. However the green anoles have been able to adapt—at least for the time being. When brown anoles are present, native green anoles move vertically up in the habitat. This allows the lizards to partition the area and decrease competition. However, if there is nowhere in the habitat for the green anoles to move, they ultimately disappear from the area. And while brown anoles are known to prey on young green anoles, their more rapid reproduction may be giving the Cuban cousins another competitive advantage.

Eradication of Cuban brown anoles is impossible at this point; they are too widely distributed. But don’t let that stop you from providing our native green anoles with adequate habitats, like tall shrubs and trees, that allow them to move up in the environment away from the brown anoles. Gardeners shouldn’t get too down about this shift in lizard dominance, though. Both species are beneficial garden predators, catching and eating beetles, flies, spiders, roaches, and other small invertebrates. So while it is interesting to know that the Cuban brown anoles are out-competing the green anoles, don’t worry that there’s not much that can be done to rid your landscape of these invaders.

More about these two competitors

The green anole is commonly found in natural and suburban habitats through the state. These lizards are great climbers, which has helped them adapt to the introduction of Cuban brown anoles.

Adult green anoles grow to 5 to 8 inches long and males have a solid pink dewlap, or throat fan. While many people call these lizards “chameleons” because they can quickly change from bright green to dull brown, green anoles are not true chameleons, which are native to Africa and Madagascar.

The Cuban brown anole, often just called the brown anole, arrived in Florida as a cargo hitchhiker more than 100 years ago. Beyond that first introduction, studies of their DNA suggest there have been as many as seven additional invasion events of brown anoles into the state. Since its arrival, this small lizard has spread across Florida; today they can be found in both disturbed and natural habitats. Adult brown anoles are 5 to 8 inches long and are various shades of brown that is flecked with greys and browns. However, unlike the native green anoles, these lizards cannot change color. Male brown anoles have an orange dewlap with a white or yellow border. Besides the color difference, brown anoles are distinguishable by their shorter snouts.

Also on Gardening Solutions

• How Can My Yard Contribute to Community Ecology?

More from UF/IFAS

• Cuban Brown Anole — The Invader Updater, Winter 2011 (pdf)
• Nonnative Reptiles in South Florida: Identification Guide

Elsewhere on the Web

• Anolis carolinensis, Green Anole–Animal Diversity Web, University of Michigan