Headstarting and Release

Captive breeding for conservation, headstarting, reintroduction, and relocation are all important conservation measures that have helped to ensure the survival of threatened iguanas. Conservation captive breeding measures are best suited for situations in which nesting sites are unavailable, threatened, or the population is so small that individuals are unable to find each other for reproduction. Alternatively, headstarting, rearing of juvenile iguanas in captivity until they reach a certain size, can be applied when reproduction in the wild is not limited, but hatchling survival is low due to increased threats faced by younger individuals. These threats are often invasive species, such as cats and mongoose, that can successfully depredate small iguanas but not larger individuals. Reintroduction often follows captive breeding and headstarting and is the act of returning individuals to a known location. Relocation, however, refers to moving individuals to a new location and is often used when a population is threatened in a given area and must be removed as a mitigation strategy or there is a need to found a new population in a new area, such as an assurance colony. These four strategies are often used in conjunction with one another to provide the most effective conservation and management approach.

Headstarting has been the most common of these strategies in iguana conservation as increased hatchling mortality due to invasive species 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 was formed in 2001, we have supported captive breeding, headstart, and reintroduction programs to build facilities, train keepers, provide veterinary support, and monitor nutrition and growth for the Jamaican Rock Iguana, Anegada Rock Iguana, Grand Cayman Blue Iguana, St. Lucian Iguanas, Lesser Antillean Iguana, and the Motagua Valley Spiny-tailed Iguana. The IIF has also supported relocation research and efforts in the Bahamas and the Turks and Caicos Islands. These conservation strategies have also been implemented for the Mona Rhinoceros Iguana, Galapagos Land Iguana, Fiji Crested Iguana, Utila Spiny-tailed Iguana, and the Five-keeled Spiny-tailed Iguana.