Do headstart programs work? Survival and body condition in headstarted Mona Island iguanas Cyclura cornuta stejnegeri

Published source details Pérez-Buitrago N., García M.A., Sabat A., Delgado J., Álvarez A., McMillan O. & Funk S.M. (2008) Do headstart programs work? Survival and body condition in headstarted Mona Island iguanas Cyclura cornuta stejnegeri. Endangered Species Research, 6, 55-65.
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This study is summarised as evidence for the following.

	Action	Category
	Head-start wild-caught reptiles for release: Snakes & lizards Action Link

Head-start wild-caught reptiles for release: Snakes & lizards

A controlled study in 1999–2006 in a subtropical dry forest site on Mona Island, Puerto Rico (Pérez-Buitrago et al. 2008) found that some released head-started Mona Island iguanas Cyclura cornuta stejnegeri survived up to five years in the wild and at least two reproduced successfully. Twenty-five of 62 (40%) head-started iguanas (15 females, 10 males) were re-captured between 8–61 months following release. Two head-started females produced clutches of 8 and 11 eggs each, and 86–91% of eggs hatched successfully. Body condition of head-started iguanas was higher before release than wild iguanas but was similar at their first capture post-release (data reported as condition index). Sixty-two hatchlings were collected from the wild by digging up nests in October 1999 (8 nests) and 2000 (6 nests), and transported to fenced enclosures. Hatchlings were marked with PIT tags and weighed and measured every 4 months while in captivity. Iguanas were marked and released at their nesting site in April 2002 and October 2003 after reaching at least 620 g and 225 Snout to vent length (about 3 years of age). Seven mid-sized and 31 adult wild iguanas were also captured and measured. Intensive trapping was conducted during 2–3 months in 2003–2006.

(Summarised by: Maggie Watson, William Morgan)