Establishing a new wild population of tuatara (Sphenodon guntheri)

Published source details Nelson J. N., Keall S. N., Brown D. & Daugherty C. H. (2002) Establishing a new wild population of tuatara (Sphenodon guntheri). Conservation Biology, 16, 887-894.
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This study is summarised as evidence for the following.

	Action	Category
	Head-start wild-caught reptiles for release: Tuatara Action Link
	Translocate adult or juvenile reptiles: Tuatara Action Link

Head-start wild-caught reptiles for release: Tuatara

A study in 1995–2000 on an island in New Zealand (Nelson et al. 2002) found that most head-started tuatara Sphenodon punctatus survived at least five years following release. Twenty-eight of 50 head-started juveniles (56%) were recaptured over six years following release, as well as 11 of 18 translocated adults (61%). Juvenile weights increased by approximately 100 g (up to 106% increase) in the five years after release. No successful breeding was observed during the six-year period, though tuatara take 10–15 years to reach maturity. In November 1995, fifty head-started juveniles were released on Titi island (a rodent-free island), along with 18 adults translocated from North Brother Island. Juveniles were selected from those hatched and reared from eggs harvested from the wild population on North Brother Island in 1989–1991. Tuatara were released into artificial burrows at night (2100–2230 h). Six post-release monitoring trips were conducted between November 2995 and November 2000, when a team of 3–4 people spent up to seven nights on the island searching for tuatara.

(Summarised by: Maggie Watson, William Morgan)
Translocate adult or juvenile reptiles: Tuatara

A controlled study in 1995–2000 on an island in New Zealand (Nelson et al. 2002) found that most translocated tuatara Sphenodon guntheri survived at least five years following release but did successfully breed. Eleven of 18 adults (61%) were recaptured over six years following release, as well as 28 of 50 head-started juveniles (56%). Following translocation, adults increased in weight by 41%, and two years after translocation they were heavier than equivalent length individuals from the founder population. No successful breeding was observed during the six-year period, though tuatara are an extremely long-lived species (up to 100 years). In November 1995, eighteen adults (11 females, 7 males) were translocated from North Brother Island to Titi Island (a rodent free island), along with 50 head-started juveniles. Tuatara were released into artificial burrows at night (2,100–2,230 h). Six post-release monitoring trips were conducted between November 1995 and November 2000, when a team of 3–4 people spent up to seven nights on the island searching for tuatara.

(Summarised by: Maggie Watson, William Morgan)