The National Trust’s Blue Iguana conservation program began with successful captive breeding in 1990, and this has remained a core part of the program ever since. Captive breeding serves three main functions in the effort to save the Blue Iguana:
- It generates young iguanas which can be released to boost existing wild populations, and to establish new wild populations in protected areas.
- It generates young iguanas which can be reared to adulthood in captivity, to ensure continuity in breeding for ongoing conservation work.
- It provides a stock of genetically managed animals which can be used gradually to establish a backup captive population in collaborating zoos overseas.
The Trust’s original captive breeding facility at the Queen Elizabeth II Botanic Park was built in 1995-6, with a large open enclosure built with a grant from the World Wide Fund for Nature, WWF-UK, and a complex of cages built with joint grants from the Zoological Society of Milwaukee County, and their partners in conservation, the Foundation for Wildlife Conservation. In 2003-4 the facility was expanded to add 14 large open breeding and holding pens, and an enclosed area with 102 cages for second-year juveniles. Support for this major expansion came from many sources, including Maples Finance, the Disney Wildlife Conservation Fund, the AZA Conservation Endowment Fund, donors to the International Iguana Foundation, Woodland Park Zoo, the International Reptile Conservation Foundation, Tulsa Zoo, Wharton-Smith Inc., and the International Iguana Society. The facility can now house 100 hatchlings, 100 second year juveniles, and about 40 adults. It is operating close to capacity.
Rearing Blue Iguanas in captivity is an evolving art – but always aided by hard science. Here (left to right) Rick Hudson (Fort Worth Zoo), Lisette Ramos (Bronx Zoo) and Bonnie Raphael (Wildlife Conservation Society) are drawing blood samples to assess health and nutritional status of the captive animals.
Each captive Blue Iguana has an internal “PIT” tag, a passive induction transponder in a tiny glass capsule, embedded beneath its skin. This provides a permanent identity marker, vital to maintaining careful records of health, growth and breeding.
In the early years of the Program we bred about 10 to 20 new iguanas annually, depending on the age and number of breeders we paired up. In 2002, breeding by released iguanas in the QE II Botanic Park boosted production, and we successfully hatched 30 young. In 2003 improvements in care kicked in and we hatched 84 baby Blues, and in 2004 we are on course to hatch a similar number. Our target is to hatch and rear 100 per year. Of these, the majority are destined for release to the wild, after 2 years in captivity during which they grow large enough to be safe from snakes and cats.