Headstarting and Reintroduction

There are four main strategies typically used for increasing populations of endangered iguanas. They are often used in conjunction with one another to provide the most effective conservation management approach.

Captive breeding for conservation, headstarting, reintroduction, and relocation is an important method that has helped to ensure the survival of threatened iguanas. It is best suited for situations in which nesting sites in native habitat are unavailable or seriously threatened, or the population is so small that individuals are unable to find each other for reproduction.

Headstarting has been shown to be a very effective conservation method. Headstarting is the raising of hatchlings and juvenile iguanas in safe surroundings under human care until they reach a size when they can better fend for themselves, increasing survival rates. This method can be applied when reproduction in the wild is not limited, but hatchling survival is low due to  threats faced by young animals. These threats are often invasive species introduced by humans, such as cats, rats, and pigs, that can easily prey on small iguanas but not adults.

Reintroduction often follows captive breeding and headstarting. It involves releasing individuals to a known location in the natural habitat. Animals that are reintroduced are usually tagged so they can be identified and tracked, to follow the success of their reintroduction.

Relocation refers to moving animals from one location to a new one. This method is used when a population is threatened in a given area, and it must be removed for safety. It may also be used if there is a need to start a new population in a new area, such as an assurance colony, so that not all individuals of a species are only in one place. 

In iguana conservation, headstarting has been the most common of these strategies. Increased hatchling mortality due to invasive predators is a major threat to many iguana species. When undertaking a headstarting program, biologists protect natural nest sites, and then collect hatchling iguanas after they emerge, move them to the safe confines of captivity and raise them until they are large enough to survive predator attacks in the wild.

Since the IIF formed in 2001, we have supported captive breeding, headstarting, reintroduction programs, and ongoing conservation research studies for more than a dozen different iguana species, including the Jamaican Rock Iguana, Anegada Rock Iguana, Grand Cayman Blue Iguana, St. Lucian Iguanas, Lesser Antillean Iguana, Spiny-tailed Iguanas, Galápagos land and marine iguanas, and Fiji Iguanas. We have helped to build facilities, train staff, fund researchers, provide veterinary support, and monitor nutrition and growth of hatchling and adult iguanas.