Scales & Tales with
Contributing Writer
Sophie Mckee
Hello, everyone. Sophie here with this month's cold-blooded creature, the spiny iguana. These big lizards are native to Mexico and all of Central America and are now another invasive species here in Southwest Florida. They may not be as famous as more common green iguanas, but spiny iguanas have their own unique characteristics that make them just as interesting.
They get their name from the sharp, keeled spines that run along their backs and tails. These spines are more than just decoration—they serve as protection against predators and help the iguanas appear larger and more intimidating.
Their bodies are muscular and built for speed, which is one of their most notable traits. In fact, spiny iguanas are considered some of the fastest-running lizards in the Western Hemisphere, capable of sprinting quickly to escape danger. They will even run on their hind legs which really makes them look like dinosaurs.
In their native countries, they are found in a variety of environments including dry forests, rocky hillsides, and coastal regions. They are really adaptable. Spiny iguanas rely heavily on sunlight to regulate their body temperature, so they spend much of their day basking on rocks, tree branches, or even rooftops.
Their coloration—usually a mix of gray, brown, and black—helps them blend into their surroundings, offering camouflage from predators such as birds of prey, snakes, and larger mammals. Feral cats and dogs also eat a lot of them.
While most iguana species are vegetarians, younger spiny iguanas often eat insects and small animals to support their rapid growth. This combination of plant and animal food makes them omnivores, and their feeding habits play an important role in their ecosystems. By eating fruits and spreading seeds from their droppings, they help maintain plant diversity. At the same time, their insect consumption helps control certain populations of beetles and grasshoppers.
Male spiny iguanas are much bigger than females and will fight each other during their breeding season. Females typically lay their eggs in burrows dug into sand or loose soil. After laying the eggs, the mother leaves them on their own, like most reptiles. The babies are about 6 inches long when they hatch and and bright green for a few years. They hide up in the trees but most still get eaten by predators.
The spiny iguana in the photos is a big male who hung around a villa we rented last month down in Costa Rica. He was obviously used to people and would eat right out of your hand, just like almost every other animal and bird we met down there.
They do have a lot of sharp teeth and claws so this really isn't the best idea, but I can't help it. He even came running up to us when we were walking back from the beach, which was really cool.
Spiny iguanas were brought to Florida from Mexico as pets, and you know the rest. I've seen a few of them near our house in Cape Coral and they are all over the sand dunes up in Boca Grande. Even though they look mean, they are harmless to people unless you try to grab one.
They will dig deep holes in your yard and eat anything with flowers, so that makes them a problem for some people. The recent cold snap probably didn't affect them at all, like it did for the falling green iguanas, so they're probably here to stay. But hey, there are worse things running around out there.
That's all for this month. See you next time with another cold-blooded creature.
Sophie Mckee
Oasis High School, Cape Coral
