New Zealand Tuatara Reintroductions
Tuatara (Sphenodon punctatus)
Tuatara (photo: Tony Whitaker) are confined to about offshore islands in the Marlborough Sounds area and along the northern east coast of the North Island. They have recently been reintruduced to two islands following predator eradications:
Moutohora (Whale) Island (143 ha, off east coast of North Island). Reintroduction. 32 wildcaught adults from Moutoki Island (0.8 ha) released October 1996. Presumed suitable habitat following eradication of rabbits and Norway rats in the early 1990s. Cats and goats had been eradicated earlier. There have also been reintroductions of red-crowned parakeets in 1986, saddlebacks in 1996, and nine threatened coastal plants in 1999. The release was designed to test the importance of environmental factors vegetation type and seabird burrow dispersion/ density on initial success of translocation. Most tuatara survived the first two years, but it's unclear whether young have been produced yet. See Owen 1998b or Owen 1999 (Reintroduction News 17: 16-18). Contact Graham Ussher for further results.
Whakau (Red Mercury) Island (Mercury Group, off NE North Island). Reintroduction. Presumed suitable habitat following eradication of Kiore in 1992. 9 captive adults originally caught on Whakau and 12 juveniles bred from Whakau animals released November 1996. Another 2 captive adults were released in December 1998. The release was deisgned to test the importance of vegetation and burrows (as above) on translocation success. It was also to assess merits of captive breeding and release programmes for juveniles. Contact Graham Ussher.
Tiritiri Matangi Island (220 ha, Hauraki Gulf east of Auckland). Reintroduction. 60 adult tuatara from Middle Island (Mercury Group) were released on 25 October 2003. Contact Graham Ussher.
Whakaterepapanui Island (outer Pelorus Sound, Marlborough Sounds). In October 2004, 300+ juvenile tuatara were released on Whakaterepapanui in outer Pelorus Sound. These animals had been hatched in captivity from eggs taken from Stephens Island in Cook Strait (as part of study by Nicola Nelson on effects of temperature on sex determination). The young animals were then raised for the next 4-5 years at Nga Manu Sanctuary north of Wellington with funding assistance from the Zoological Society of San Diego. The release site was some 500 m from where adult tuatara had been released the previous year. While the establishment of another wild population of tuatara has obvious conservation benefits for the species the population will be of particular scientific interest in helping to determine whether the fitness of captive raised animals differs from those raised naturally. From Peter Gaze.
Karori Wildlife Sanctuary (225 ha mainland restoration area surrounded by a mammal-proof fence, central Wellington, North Island). Reintroduction. 70 tuatara were translocated to Karori Wildlife Sanctuary in Wellington on 2 December 2005. The reintroduction is part of the restoration program in the sanctuary following eradication of mammals inside the fence (see http://www.sanctuary.org.nz). This is the first reintroduction of tuatara to any mainland site since they were extirpated from the mainland in the 19th century. The tuatara came from Stephens Island. After quarantine, 60 animals were released into a specially constructed mouse-free enclosure of ca. 1 ha size, and 10 tuatara were released outside this enclosure, to examine whether the tuatara could survive in the presence of mice (a MSc project). 6 animals inside and 10 animals outside the enclosure were released carrying transmitters to assist with monitoring survival and condition. Animals caught since release have had no significant change in condition but external parasite loads have been reduced; no mouse damage has been detected. Another 130 tuatara from Stephens Island will be released in Karori Wildlife Sanctuary in the future. Contact Raewyn Empson or Katie McKenzie.
Brothers Island Tuatara (Sphenodon guntheri)
Brothers Island tuatara (photo: Alison Cree) was described as a separate species in 1877. Nevertheless, legislation and management treated all tuatara as a single species until recently. Follwing analysis of allozyme and morphological variation in tuatara from 24 islands (Daugherty et al. 1990, Nature 347: 177-179), the tuatara on North Brother Island became generally recognised as a separate species from other tuatara. North Brother is a 4 ha island in the Marlborough Sounds, between the North and South Islands of New Zealand. The island supports about 350 adult tuatara, and the population has a high probability of long-term survival (Nelson 1998). Translocations are being used to establish populations on other islands where the species may have occurred historically.
Titi Island (32 ha, Marlborough Sounds, off NE South Island). 68 tuatara were translocated from North Brother to Titi Island, Marlborough Sounds, in 1995. It is likely (but not confirmed) that tuatara would have occurred on Titi historically, but it's unclear which species would have occurred there. Tuatara would have been exterminated by Norway rats, which were eradicated from 1970-75. Tuatara had high survivorship and improved in condition in the first two years after release, suggesting a high probability of population survival (Nelson 1998). Contact Nicky Nelson.
Matui-Somes Island (25 ha, Wellington Harbour). 20 wildcaught adults from North Brother Island and 34 captive-reared juveniles released October 1998. Tuatara were recorded historically on Matui-Somes, but the species/genetic group is unknown. The island was mostly cleared of vegetation, and had ship rats which would have exterminated tuatara. The rats were eradicated in the early 1960s, and Forest and Bird have been doing a revegetation programme since 1981. Contact Charlie Daugherty or Peter Gaze.