Anolis cristatellus

Anolis cristatellus, commonly known as the crested anole or the common Puerto Rican anole, is a small to moderately-sized lizard native to Puerto Rico and the U.S. and British Virgin Islands. This adaptable species is characterized by its ability to thrive in a variety of habitats, including urban environments, where it can frequently be observed on tree trunks, fences, and the walls of buildings.

Key Characteristics

Male Anolis cristatellus are readily identifiable by their prominent, permanently erect caudal crest, a distinctive fin-like structure running along the top of their tail. They also possess a colorful dewlap, a throat flap that they inflate to display dominance, attract mates, or intimidate rivals. While females also have a crest and dewlap, these features are typically smaller than those of the males. The species exhibits sexual dimorphism, with males generally being larger and more ornate. Anolis cristatellus is also known for its ability to change color, shifting from light gray to dark brown or black in response to its emotional state, a trait that has led some to mistakenly refer to them as chameleons, though they are not related.

Habitat and Distribution

This anole is found in nearly all habitats across Puerto Rico and the Virgin Islands, ranging from open fields to rainforests, though it generally decreases in abundance at higher elevations. Introduced populations have established themselves in other Caribbean locations, including Costa Rica, Trinidad, and parts of Hispaniola and Dominica. In these introduced ranges, they often show a strong preference for urban and disturbed areas. The species is classified as a 'ground-trunk anole,' meaning it spends a significant portion of its time on the lower sections of tree trunks but will descend to the ground to forage and lay eggs.

Behavior and Diet

Anolis cristatellus is oviparous, reproducing by laying eggs. As they grow, they shed their skin and often consume the shed skin, a behavior thought to conserve nutrients. Defensively, they can autotomize, or break off, their tails to escape predators; these regrown tails are supported by cartilage rather than bone. While not particularly vocal, they can produce chirping sounds. Their diet consists of various prey items, and they have been documented consuming relatively large prey such as blindsnakes and juvenile anoles.

Conservation and Human Interaction

Anolis cristatellus is considered an extremely common species in its native range and may have become even more prevalent as human development has created more of its preferred habitats. While generally not considered invasive, its introduction to islands like Dominica has raised concerns about its potential to outcompete and displace native anole species. They are also sold globally in the pet trade. The species is present in several protected areas, including nature reserves and national parks in Puerto Rico and the U.S. Virgin Islands.