International Iguana Foundation Conservation Features

Anegada Iguana

The Fort Worth Zoo has been involved in conservation of the endangered Anegada iguana (Cyclura pinguis) for several years. In 1998, Zoo staff traveled to Anegada in the British Virgin Islands, as part of a team sponsored by the West Indian Iguana Specialist Group. The team worked to construct a facility that could be used to headstart young iguanas. Headstarting has increasingly become a viable component of the recovery strategies for endangered rock iguanas, especially where the primary threat is high juvenile mortality associated with predation by introduced exotics. The facility provides a place where the iguanas can be raised until they are large enough that predation will not be as much of a threat. Once they reach a certain size, the iguanas are released into the wild.

Zoo staff have traveled back to the facility many times to conduct research. Most recently, Fort Worth Zoo veterinarians and nutritionists visited Anegada with a team from the St. Louis and Dallas Zoos. Several projects brought this team together. The first, “Nutritional Assessment of Free-ranging and Headstarted Iguanas (Cyclura pinguis) on Anegada,” involved the collection and analysis of native plants to obtain a representation of nutrient intake by free-ranging iguanas. The study, funded by a grant from the Bergen County Zoo, also involved a four-day diet intake study to determine nutrient intake of iguanas at the headstart facility.

The second study, “Health Assessment of Free-ranging and Headstarted West Indian Iguanas,” involved the collection of growth data, blood, fecal and bacterial culture samples from both headstart and free-ranging iguanas. This data will allow veterinarians to determine the overall health of the headstart iguanas and to determine their readiness for release to the wild. This project was funded by a grant from the Morris Animal Foundation.

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Grand Cayman Blue Iguana

Prompted by alarming new statistics on the population of the Grand Cayman blue iguana, scientists sponsored by the International Iguana Foundation (IIF) are mobilizing a response to this crisis that could involve the removal of the last remaining wild specimens to the safety of captivity. In a report issued June 22, 2002 by the National Trust for the Cayman Islands, it is estimated that only 10 to 25 blue iguanas remain in the wild (down from 100 to 200 estimated in a 1993 survey). The new population figures make blue iguanas one of the most critically endangered reptile species in the world.

Once in abundance, iguana populations throughout the Caribbean Islands began to decline with the advance of colonization. The situation on Grand Cayman is compounded by rapidly expanding development on the small island. The few remaining blue iguanas are isolated in small habitat pockets. Uncontrolled feral cats kill most of the young iguanas, while some of the adult iguanas are killed by free-ranging domestic dogs or hit by cars while basking on new roadways as the human population expands throughout the island.

The short-term outlook for this rare iguana will likely depend on captive programs, both in Grand Cayman and the U.S. The Rock Iguana SSP program will maintain a stable and genetically diverse captive population of 225 iguanas as a hedge against extinction in the wild. The National Trust for the Cayman Islands has managed a captive breeding facility on Grand Cayman since 1990, producing small numbers of iguanas that are being released annually in the adjacent Queen Elizabeth II (QEII) Botanic Park. The released population has now grown to some 30 animals.

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Jamaican Iguana

Rediscovered!

The Jamaican iguana was rediscovered in 1990 when a dog belonging to Edwin Duffus, a pig hunter, carried one home in its mouth. This discovery made a huge impact in the field of conservation because this species had been considered extinct for nearly 50 years. A remnant population was found surviving in the remote area of Hellshire Hills along Jamaica's southeastern coast. This population exists today in a 100 square kilometer area of tropical forest ecosystem that is being degraded and fragmented due to local charcoal burning industry. Additional threats to this small population include high juvenile mortality from mongoose predation as well as over-hunting and habitat loss. The Jamaican iguana is considered one of the most critically endangered reptiles in the world and remains on the brink of extinction.

Headstart program

There are two known iguana nesting sites in the Hellshire Hills. After the females nest in June, the sites are guarded against predators. As the hatchlings emerge in September, many are collected for headstarting in captivity.

In May 1994, a six-man crew from the Fort Worth Zoo constructed an iguana management facility at the Hope Zoo that allowed them to expand their headstart program. Iguanas are brought to the facility as hatchlings and then released when they are large enough to avoid mongoose predation. More than 100 hatchling iguanas have been raised here for eventual release into the wild.

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