Grand Cayman Blue Iguana
Cyclura lewisi
IUCN Status: Endangered
Range: Grand Cayman, Cayman Islands
Population: ~450 adults
Size: Males up to 22 lbs.
Threats: Predation by feral dogs and cats; road traffic; habitat conversion
Conservation Measures

The Grand Cayman Blue Iguana, while still endangered, is an ongoing conservation success story. This powder-blue species once numbered only 10–25 animals left in the wild. Thanks to an ambitious and concerted conservation program — funded in part by the IIF — the wild iguana population of Grand Cayman is now rebounding, with evidence that natural breeding is occurring.

The Grand Cayman Blue Iguana had been in decline for decades due to the impacts of feral predators (cats and dogs), domestic livestock, habitat disturbance and destruction, trapping and shooting by farmers, road collisions, and collection for the pet trade. But the critical status of the species was not fully understood until a 2002 wild population survey, at which point it was considered functionally extinct in the wild. A handful of animals were held by U.S. zoos and in a small captive facility located in the island’s Queen Elizabeth II Botanic Park.
To save the iguana, the National Trust for the Cayman Islands partnered with government colleagues, U.S. zoos, and donors (such as the IIF) to form the Blue Iguana Recovery Programme (BIRP) and a Species Recovery Plan was developed. The ground-breaking BIRP efforts, while encountering serious hurdles over time, succeeded wildly in breeding selected pairs, artificially incubating the eggs, and raising the hatchlings in captive safety. The National Trust also took a major step by creating the Salina Reserve and Collier’s Wilderness Reserve protected areas in the island’s eastern end. Captive-raised iguanas have been released to these two areas as well in the QEII Botanic Park. To encourage site fidelity, iguanas are released in specially constructed wooden hide boxes that also provides a measure of safety against feral dog and cat attacks. In July 2018, the 1,000th Grand Cayman Blue Iguana named “Renegade” was released into the wild, in the Collier’s Wilderness Reserve.
Ongoing conservation needs for the iguana include increased research to manage the species remaining genetic diversity, continuous education and outreach efforts to ameliorate ongoing threats to the species such as road mortality, and the possibility of harmful impacts by the invasive Common Green Iguana (Iguana iguana).
Reports from the Field
IIF Grants Received