The long term goal of the Trust’s Blue Iguana program is “to restore a wild population of the Grand Cayman Blue Iguana sufficient to remain viable in the long term.”
In practical terms, that means protecting habitat for the iguanas, alleviating un-natural pressures and threats on them, and then doing everything possible to encourage a rapid recovery in numbers.
Populations of the Grand Cayman Blue Iguana have been in decline for well over a century, due to the loss and fragmentation of habitat that have followed advancing civilization. Introduced predators such as rats, cats and dogs destroy nests and kill juveniles and adults, leaving few young iguanas surviving to reproductive age. However captive breeding by the Blue Iguana Recovery Program has been increasingly successful in recent years, and releases into a small managed, protected area has proved successful. The Blue Iguana Recovery Program has thus shown it is possible to save this unique and magnificent species from extinction.
Techniques for releasing captive bred Blue Iguanas were first tried out in the Salina Reserve, a 625-acre nature reserve in Eastern Grand Cayman which is owned and protected by the National Trust. Three captive bred 3-year-old iguanas, which had only experienced life in a cage and an artificial diet, were fitted with temperature sensitive radio transmitters and carefully released into a mosaic of soil patches among the dry forest.
For two months the iguanas were tracked and studied as they adjusted to life in the wild. The results were remarkable! The iguanas rapidly figured out what was edible from the vast array of plant life on the site, and settled down to a diverse diet quite similar to what we had observed in wild iguanas. They claimed and defended rock holes which they used as overnight retreats, established territories, and within weeks were behaving as if they had never known any other life.
For practical reasons the next year the focus of operation was switched to the Queen Elizabeth II Botanic Park, a 65-acre park with natural forest, wetland, nature trails, flower gardens and open areas. Starting in 1996 the Program released small numbers of Blue Iguanas annually into the Park, of which about 30 have now settled within the Park boundaries. In 1999 the first breeding by released iguanas took place in the Park – a landmark sign of early success.
Ongoing studies being carried out by Program researchers have highlighted the need to create artificial nesting sites in the Park, and to improve food availability to females occupying small, restricted territories. With these improvements, and a limited number of additional releases from the captive breeding program, all seems to be on course for the Botanic Park to sport a small self-sustaining population, living in harmony with people in a man-modified environment. The Park is now close to its carrying capacity for Blue Iguanas.
With the restocking of the Botanic Park deemed a success, it was time to return to the Salina. Survey work in early 2004 discovered more suitable Blue Iguana habitat in the reserve than had previously been realized. In summer 2004, with grants from the Dennis Curry Charitable Trust (via the Durrell Wildlife Conservation Trust), and from the International Iguana Foundation, work began to release 25 two-year-olds from the captive program into the harsh, rocky shrubland of the reserve’s northern sector. In years to come we hope these will be the first founders of a second restored wild population of Blue Iguanas, roaming again where their ancestors once thrived.