Tuatara lay clutches of eggs, 5-18 eggs can be laid under the ground's surface and abandoned to hatch 12-14 months later.
Females require at least two (have also laid annually) years between laying, which is
usually in October or November. Mating occurs in February and March.
In captivity at the Southland Museum and Art Gallery, everything is artificially
The egg carrying female is injected with Oxytocin to induce her to lay her eggs. The eggs
are carefully incubated. Controlled moisture and temperature ensures maximum results.
Sexual maturity is 16 years. In captivity, with good feeding they reach this size much
sooner (9-12 years compared to 18-22 years in the wild).
Unlike lizards, tuatara do not have a copulatory organ. Fertilization requires the male to
position his cloaca (vent) opposite the female's cloaca.
Males are distinguished by their size, with an adult male being twice the size of a female. The male also has a larger crest.
During courtship the male displays himself by inflating his trunk and throat. His
crest is also elevated. He walks in a circle around the female, one step at a time, after each step lifting his body off the ground. If the female is receptive she has eggs ready to fertilize. A nod of her head to
the displaying male will instantly result in copulation.
A similar display to that of mating but the throat is more inflated and the movements
more rapid. Fighting tuatara will strategically move side by side lunging at one another's neck or head. They also "croak" as they attempt to defend themselves or escape from a lock-on bite.
Studies on tuatara would indicate that 50-60 years may be required to become fully
grown and possibly live 200-300 years! Like lizards, tuatara can shed their tail. The tail does not completely regenerate back to normal.
Tuatara are nocturnal – they become active after sunset. By day they will bask in the
sun outside their burrow. Any insects that walk past are likely to be consumed.
Tuatara do not have separate teeth but sharp serrations on the bone. Their bite is
very strong and can hold a vice-like grip for a long period of time.
Tuatara do not like temperatures in excess of 25C and are active in cool temperatures
where other reptiles and lizards would not be. They have the ability to hibernate if the temperature becomes too cool, below 5C.
Tuatara are territorial with each animal having its own underground burrow.
Third Eye (pineal eye)
On top of a tuatara skull above the brain, is a third eye. This is a complex organ
which actually has a lens and retina. It is visible through the skin of newly hatched tuatara but as they grow is covered over with opaque scales. This may act more like a pineal gland which detects the seasonal
changes by the length of daylight and darkness.