The first known tuatara (Sphenodon punctatus) nest in over 200 years on the mainland has been found at Karori Sanctuary in New Zealand.
The nest contains at least 4 eggs but it is likely to contain more, as tuatara usually lay around 10 eggs at a time.
Staff at the wildlife sanctuary uncovered the nest accidentally.
“We knew of two suspected nests but didn’t want to disturb them to confirm whether or not they contained eggs. The nest in this photo was uncovered by accident, and is the first concrete proof we have that our tuatara are breeding. It suggests that there may be other nests in the Sanctuary we don’t know of.” said Sanctuary Conservation Manager Raewyn Empson.
The eggs were immediately covered up again to avoid disturbing their incubation. Sanctuary staff say that the eggs would have been laid almost exactly a year ago. Female tuatara lay their eggs into a shallow trench and then backfill it.
Native to New Zealand, the tuatara is a reptile with distinctive soft spines down its backbone. Although it looks superficially like a lizard, tuatara is actually the only surviving member of the order Sphenodontia.
Tuatara are greenish brown, and measure up to 80 cm (32 in) from head to tail-tip. It can take as many as 30 to 35 years for a tuatara to reach full size. This makes it the slowest growth rate of any reptile.
Tuatara usually lives to around 60 or 70, but they have been known to live to more than 100. In fact, one tuatara was seen mating last year at the ripe old age of 111.
The tuatara’s ancestory dates back to the dinosaur time. Ancestors of the tuatara and many other sphenodons were roaming the world 225 million years ago. This was about the time the first dinosaurs appeared.
All other sphenodons disappeared around 65 million years ago and exist only as fossils. As a result, scientists often refer to tuatara as “living fossils”.
Tuatara Mating & Breeding
Staff at the wildlife sanctuary suspected that tuatara were about to breed. They witnessed tuatara mating for the first time in March/April last year. Then around this time last year, they witnessed a female tuatara carrying eggs.
Tuatara reach sexual maturity at around 10 to 20 years of age.
The female, on average, lays between 5 and 18 eggs only once every 4 years, which gives it the longest reproductive cycle of any reptile.
Mating season for tuatara is between January and March. Female tuatara then lay their eggs between October and December. Hatchlings appear between 12 to 15 months later.
Tuatara - Threatened Species
The nest is a significant find for New Zealand because, until the sanctuary was established in 2005, the tuatara was thought to have been extinct on the mainland.
The tuatara, which only occurs in New Zealand, was almost wiped out by rats - an introduced species - by the 1700s. In fact, in 1895, the tuatara was one of the first animals in the world to become fully protected by law.
Since then, significant tuatara populations have survived on 32 remote islands around New Zealand.