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I've just been reading what I had up on the web! Its about time I rewrote my webpage!!! The tuatara is unique to New Zealand. The similarity in morphology to other Sphenodontians from 200 million years ago suggests a evolutionary conserved species. Although the sole representative of the Sphenodontia Order it is known that the Sphenodontians were quite speciose around 200 million years ago. Initially thought of as a lizard, there are enough differences to term the tuatara a lizard-like reptile.The species status of the tuatara has been one of naming, renaming, subspecies, species, trinomials - the works! Recent work has settled on: reinstatement of Sphenodon guntheri (only present on North Brother Island, Cook Strait), and two groupings of Sphenodon punctatus. The first grouping, the Cook Strait group, is on four islands near North Brother Island and contains the largest concentration of tuatara on Stephens Island (estimates range from 25-50,000 - it is a large island!). The second group are on a number of islands off the northeastern side of the North Island, around 25 islands contain tuatara - although some are quite decimated and may contain only a handful of animals. The current Department of Conservation recovery plan for tuatara lists the northeastern populations as S. p. punctatus. Reports that tuatara were spotted around Mount Victoria (Wellington) in the 1840's, and in Makara in 1864 indicate that tuatara were sympatric with the European - albeit briefly. The main cause of the tuatara decline is the rat (in its three forms), the Maori 'kiore' being the most likely culprit in decimating populations. Tuatara can take up to 2 years to produce an egg, and then another 10 before breeding age is attained, the rat by eating young tuatara (or eggs) would effectively destroy a whole generation of the reptile. In keeping with NZ native fauna’s typical longevity, tuatara are estimated to live over 100 years. Although to the best of my knowledge there is yet to be a consensus on an average lifespan (either captive or wild). The most populous island with tuatara is Stephens' Island, in Cook Strait. Here they share their burrows with a bird, and take advantage of this situation by eating eggs of the bird - no one ever accused a bird of being bright! In terms of size, tuatara (male) can grow to about 70cm long, and can weigh upto 1.5kg. Tuatara eat live prey, bird eggs, birds young and old, weta's, and in the pre-history of NZ Leiopelma frogs would likely to have been in the diet. Females mate every 4 years, and can take up to 2 years to mature 1 egg. For my PhD I am looking at the chromosomes of the tuatara and what variation is present between various islands. I've currently looked at North Brother Island, Stephens Island, Ruamahua-iti, and Stanley Island representing all three groups of tuatara. I've included some pictures of these islands on separate pages to give you an indication what they look like.
Top Left : tuatara eating a gecko Top Right : tuatara hatching Bottom: tuatara and a petrel
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