This is an adult male Mexican Spiny-tailed Iguana from the Miami population.Yes, it does seem that unwanted critters come in threes to Florida—three boa species, 3 python species, and 3 iguana species.

When mentioned at all, the subject of iguanas in Florida usually refers to the omnipresent Green Iguanas of the southern peninsula and the Keys. This is understandable for these are the most easily seen as they display in the trees, on abutments, on canal banks, and just about everywhere else. But besides this attention grabber, there are 2 other species that are actually present. These are both Spiny-tailed Iguanas, ground dwellers, very efficient burrowers, speedsters, climbers if necessary, and of very similar appearance. Both species are predominantly herbivorous but will accept animal matter if hungry.

In name they are the Mexican Spiny-tailed Iguana, Ctenosaura pectinata, and the Black Spiny-tailed Iguana, C. similis. Despite the reference to color, C. similis is very similar to C. pectinata. Both are big gray lizards with darker crossbands. Both are capable of considerable color changes, being lightest overall when warm and content, and assuming darker colors when being combative or cold. The actual difference can only be ascertained by the presence or absence of small scales between the dorsal spines and spiny tail whorls. Hatchlings are green, lack a dorsal crest, but caudal spines differentiate them from the green iguana.The presence of both is, like their green relative, the result of escapees or releasees.



If you see a big (4 feet long) gray lizard basking atop a wall or rock in southern FL, you are probably viewing a spiny-tailed iguana. Say “Howdy” for me.