Blue Iguana Recovery Program

The Grand Cayman Blue Iguana: Approaching Extinction

Jul 1st, 2002 | By | Category: Blues in the International Press

By John Binns, International Iguana Foundation
July 2002

While the world focuses on more widely publicized endangered species such as whales, whooping cranes, giant pandas, and other high-profile wildlife, the Grand Cayman Blue Iguana is quietly heading for extinction in the wild. It is considered one of the most critically endangered reptiles in the world.

In a report issued June 22, 2002 by Fred Burton, Director of the iguana recovery program for the National Trust for the Cayman Islands, only 10 to 25 of these magnificent creatures remain in the wild.

The report is a result of surveys conducted between December 2001 and June 2002 as a part of the Blue Iguana Recovery Plan, a document detailing wide-ranging conservation measures for the Blue Iguana. The stated purpose of the plan is to restore a wild population of the Grand Cayman Blue Iguana sufficient to remain viable in the long term. Until the recent survey work, between 100 and 200 animals were thought to remain in the wild. That assumption was based on a survey conducted in 1993.

The new report concludes that, without intervention and immediate preventative measures, the surviving wild population will be functionally extinct within the next 5 years.

The report further states, “since 1993 the range occupied by Blue Iguanas (not including the managed population released by the Trust in the QE II Botanic Park) has shrunk from approximately 7.0 to 3.7 square kilometers, and within the remaining range the population has been reduced approximately five-fold. Many of the surviving iguanas are isolated, with only one location identified where breeding has occurred in the last two years.”

Once abundant, iguana populations began to decline with the colonization of islands in the West Indies, as the animals fell prey to human consumption and subsequently to predation by introduced feral mammals. In the wake of advancing civilization, pristine habitats were destroyed and replaced with residential and commercial developments, leaving virtually no natural habitat for the iguana.

These few remaining iguanas, isolated in small habitat pockets, are under continual attack by free-ranging domestic dogs. High juvenile mortality due to uncontrolled feral cats and rats reduces recruitment to adult ranks. This is a slow and insidious combination of factors that results in an increasingly aged population. To make matters worse, following the development of new interior roadways and increased traffic, iguanas often are killed while crossing or basking on these roads.

Mr. Burton states, “In the long term, it is clear that the future of wild Blue Iguanas must now rest on managed populations in protected areas. Sufficient protected habitat does not currently exist to support the numbers of wild iguanas that are needed to secure the future of this species. Additional protected habitat for Blue Iguanas is therefore essential.”

The National Trust for the Cayman Islands has managed a small captive breeding facility on Grand Cayman since 1990, producing small numbers of iguanas that are being released annually in the adjacent Queen Elizabeth II Botanic Park. The released population has now grown to some 30 individuals, but the Parks area is far too small to accommodate the thousand-strong population size needed for long-term viability. The program is chronically under-funded and relies on donations. Mr. Burton, who has spearheaded conservation efforts for the Blue Iguana and the breeding facility from the beginning, currently volunteers his time so that such limited funding as is available can go entirely into conservation actions.

The short-term outlook for this rare iguana will likely depend on captive programs, both in Grand Cayman (in situ) and the U.S. (ex situ). The ex situ program consists of the AZA Rock Iguana Species Survival Plan (SSP), which will attempt to maintain a stable and genetically diverse captive population of 225 iguanas as a hedge against extinction in the wild. In the absence of wild sub-populations, the SSP effectively will become the backup population. Such an effort will require a far greater commitment from the zoo community than what now exists. New dedicated iguana management facilities in warm-climate southern zoos are desperately needed.

The in situ program will need to expand the scope of its operation in order to generate larger numbers of hatchling iguanas that can be head-started for future release. With the Trust-run facility at maximum capacity, funds are urgently needed to construct new breeding and rearing enclosures. The Disney Wildlife Conservation Fund, through the International Iguana Foundation, recently awarded a grant that will pay for construction materials, but funding is still needed to complete the project.

Extinction of the Blue Iguana is not inevitable, but the conservation community and its many supporters worldwide must act decisively and quickly if we are to prevent it. Assistance, funding, and corporate sponsorships must be found to support the measures outlined in the Blue Iguana Recovery Plan. If you can help in any way, want more information regarding the Blue Iguana Recovery Plan, or are interested in making a tax-deductible donation, please visit: We still have the time and an opportunity to help restore these magnificent giant lizards to their former glory in the wild where they truly belong.

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