Culebra Island Giant Anole

Anolis roosevelti

Description

The Culebra Island giant anole is a member of a group of large tree canopy-dwelling lizards collectively termed "giant anoles" to distinguish them from their smaller relatives, also in the genus Anolis. The lizard is brownish gray with two lines on each side of the body. It has a gray throat fan that is bordered on the lower rear quarter by light yellow. The tail is yellowish brown and the belly is whitish in color. Adult males have a deeply scalloped fin along most of the tail. The body measures about 6.5 in (16.5 cm) and the tail adds another 6-7 in (15-18 cm). Weights are unrecorded.

Behavior

Nothing is known concerning the anole's biology and life history. The original collector of the type series on Isla Culebra stated that the lizards were collected high in trees where they were seen on branches. He saw them most commonly when fruits, particularly figs, were ripe. Observations on the related Anolis cuvieri of Puerto Rico suggest that most activity occurs in the tree canopy at heights of 49-82 ft (15-25 m), that home range may exceed 355 sq ft (33 sq m), and that the lizard probably has a varied diet consisting of many types of invertebrates, small vertebrates, and fruit.

Habitat

The habitat of the anole is unknown for certain except on Isla Culebra. The collector of the type specimens stated that they occurred in the tall gumbo limbo (Bursera ) and fig (Ficus ) forest on the north coast.

Distribution

The Culebra Island giant anole is known to have occurred on Islas Culebra and Vieques (Puerto Rico), Tortola (British Virgin Islands), and St. John (U. S. Virgin Islands). These islands are located east of mainland Puerto Rico on the Puerto Rico bank. Until recently, the Culebra Island giant anole was known from only two specimens collected on Isla Culebra in the early 1930s. Examination of specimens of A. cuvieri from several European museums revealed incorrectly identified Culebra Island giant anoles collected in the nineteenth century from Isla Vieques, St. John, and Tortola. Less than 10 specimens, including only one female, are known. The species has not been collected since 1932. Casual searches of northern Isla Culebra have been made as recently as 1991 without success.

Threats

Exactly why the anole is so rare, or if it is now extinct, is unknown. Although the Flamenco Peninsula, where the type specimens were collected on Isla Culebra, was deforested, patches of canopy forest remained until at least 1989 when Hurricane Hugo destroyed much remaining forest habitat. Suitable canopy forest no longer remains on St. John. However, canopy forest remains on Tortola above 1,500 ft (460 m) and probably on Isla Vieques. The anole may have been rare naturally, but human-caused deforestation, introduced predators, and natural phenomena such as hurricanes also may have affected its survival.

Conservation and Recovery

The U. S. Fish and Wildlife Service approved a recovery plan for the Culebra Island giant anole in 1982. The plan called for the protection of remaining habitat on Isla Culebra and systematic searches of the island to locate remaining populations. The plan did not address the other islands because the historic presence of the lizard on these islands was unknown when the plan was approved. Parts of the potential habitat of this species on Isla Culebra were included within the Culebra National Wildlife Refuge. Much of the island of St. John is located within the Virgin Islands National Park. To date, systematic searches have not been conducted to confirm the lizard's survival or extinction. However, there is reason to believe that it survives in remnant canopy forest on at least one of the islands from which it was historically known. The lizard's survival and status remain somewhat speculative until inventories are completed.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
http://southeast.fws.gov/

Reference

Mara, W.P. 1996. Anoles. Capstone Press, Mankato.