Saturday, November 7, 2009
Camera Critters: Tuatara
This is a tuatara and it's not a lizard. It does belong to the Reptilia class, but has it's own order, Sphenodontia - lizards (including snakes), crocodiles and turtles/tortoises are the other orders in that class. There are two species in that order, the remains of a diverse group that was in its prime 200 million years ago.
Tuatara means "peaks on the back" in Maori, Tuataras are native to New Zealand. They are very rare and very unusual. Unlike lizards, they can remain active at low temperatures and high temperatures are often fatal for them. The plates on their body are somewhere between those of a lizard and those of a crocodile. They can focus their eyes indepedentely, like a chameleon, and can see just as well during the day as during the night. They are nocturnal and will feed on insects, frogs, lizards and bird chicks and eggs.
They also have a third eye on the top of their head, a parietal eye. Many reptile species have something similar, but much less well developed, more like a light-sensitive spot (if you have a bearded dragon or an anole, take a look - you can see it). The tuatara have almost a real eye, scientific research suggest that the parietal eye did evolve from an actual eye and not the other way around. It's only really visible with juveniles, though.
Tuataras almost died out after rats (among other animals) were introduced into their habitat. Now there are breeding populations on several islands where humans eradicated all the rats and they are bred in captivity. One male named Henry is about 110 years old and still going strong, producing fertile eggs with his mate Mildred (the average lifespan is more like 60 years, though). You can visit him in Invercargill, New Zealand. I took my photos in the aquarium of the Berlin zoo, where 10 Tuataras are kept.
See more critters at the Camera critters meme