Anole, Culebra Island Giant

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Anole, Culebra Island giant

Anolis roosevelti

phylum: Chordata

class: Reptilia

order: Sauria

family: Iguanidae

status: Critically endangered, IUCN Endangered, ESA

range: Puerto Rico

Description and biology

The Culebra (pronounced koo-LAY-bra) Island giant anole (pronounced a-NO-lee), also known as Roosevelt's giant anole, is a large lizard that dwells in tree canopies (uppermost branchy layers of forests). The main part of its body is brown-gray. Its tail is yellow-brown and its belly is whitish. The anole's dewlap, or throat fan (loose skin hanging from its neck), is gray, bordered by light yellow. The adult male of the species has a scalloped fin that runs along its tail. An average adult measures about 6.5 inches (16.5 centimeters) long. The tail adds another 6 to 7 inches (15 to 18 centimeters).

Scientists know almost nothing about the Culebra Island giant anole's daily habits, reproduction, or life history. They believe it acts the same way as another species of anole in Puerto Rico. Based on observations of that species, scientists think that the giant anole is found mostly in tree canopies at heights between 49 and 82 feet (15 and 25 meters). It has a home range that may exceed 355 square feet (920 square meters). It probably has a varied diet consisting of many types of fruit and small animals.

Habitat and current distribution

The Culebra Island giant anole once inhabited Culebra and Vieques Islands (part of Puerto Rico), Tortola Island (British Virgin Islands), and St. John Island (U.S. Virgin Islands). All of these islands lie east of the Puerto Rican mainland.

Scientists are unable to estimate the total number of giant anoles currently in existence.

History and conservation measures

The Culebra Island giant anole is a rare and critically endangered species. The most recent specimens of the giant anole were collected on Culebra Island in 1932. Casual searches for the lizard on the northern section of the island in 1991 were unsuccessful.

Exactly why the giant anole is so rare, or if it is now extinct, is unknown. Although much of the forest area on Culebra Island has been cleared during the twentieth century, patches of canopy forest remained until Hurricane Hugo struck the island in 1989. Suitable forest habitat no longer remains on St. John. Canopy forest does remain on Tortola above 1,500 feet (457 meters) and probably also on Vieques. The clearing of forests by humans, introduced predators, and natural phenomena such as hurricanes have probably combined to reduce the number of giant anoles.

In 1982, the U.S. Fish and Wildlife Service approved a plan calling for the protection of remaining giant anole habitat on Culebra Island. The plan also called for systematic searches of the island to locate any remaining giant anoles. So far, those intense searches have not been undertaken. Scientists are hopeful that the Culebra Island giant anole survives on at least one of the islands in its original range.