An adult tuatara ready for release. Photo by Scott Jarvie.
For the first time in a couple of hundred years, New
Zealand's unique tuatara are free-roaming in a South Island
forest, thanks to a recent translocation of Cook Strait and
captive-reared animals to Orokonui Ecosanctuary. Sue Hensley
Tuatara are not dinosaurs, although a tuatara-like fossil
named Homoeosaurus sounds like one. Confusing? It gets worse
- saurus means lizard but neither dinosaurs nor tuatara are
In fact, the tuatara is the sole survivor of a
230-million-year-old group of reptiles known as
The other reptile orders have numerous members ranging from a
low of about 22 to several thousand species, but the tuatara
is the lone representative of its order. This is what makes
it internationally significant.
It is not surprising that the tuatara is often mistaken for a
lizard because the differences are subtle and not easily
On a physical level, the upper jaw and skull bones of tuatara
are not hinged like those of lizards but instead are rigidly
fixed. There are also two rows of teeth in the upper jaw of
tuatara, enabling a very distinctive, saw-like way of
On the other hand, like lizards, tuatara can drop and regrow
their tails, and the so-called third eye often talked about
in relation to tuatara is also found in some lizards.
As Associate Prof Alison Cree, of the University of Otago's
zoology department, puts it, the tuatara is the closest
living relative of lizards that isn't actually a lizard!
New Zealanders have always been particularly proud of the
tuatara and its standing on the world stage. It was even on
our coinage until 2007.
Its reputation is enhanced by its remarkable biology and
longevity. Any animal that lives for 100 or more years
certainly deserves respect. Males have no penis, as one boy
excitedly told an Orokonui guide. In winter, tuatara slow
right down and can go several months without food.
When cool and inactive, they have been reported to breathe as
infrequently as once an hour with a heart rate of only nine
to 10 beats a minute.
The young have a parietal eye (the so-called "third eye") on
the top of the head that is probably light sensitive but not
image-forming. The precise role of this sensory structure is
unclear, but it is possible that it helps with homing
behaviour, as in some lizards.
There have also been suggestions that it helps regulate
exposure to UV light, a form of radiation that is critical to
growth and metabolism.
The females reproduce only once every two to five years and
the usual clutch size of around nine eggs takes about a year
to hatch. The eggs cope with large temperature fluctuations
and the sex of the progeny is determined by the temperature
during incubation. The effect that climate change will have
on the sex ratios of hatchlings is an interesting question.
Looking after these creatures living in the slow lane
produces some interesting situations.
Valerie Fay over the past four years has cared for the 15
young tuatara held at Orokonui with the assistance of
researchers from the University of Otago.
One warmish day, Val entered the pen to discover one of the
tuatara lying motionless on the bottom of a water dish. On
closer inspection, however, and with a gentle prod, the
tuatara moved slightly to show that it was indeed alive. In
fact, tuatara do like to cool down or rehydrate in this way
and one was observed under the water for 20 minutes.
Then there's their general non-appearance over winter.
It's not easy to look after animals that can't be seen for up
to five months before they are sighted again in spring. When
they are actually seen during colder periods it can be just
Valerie Fay recalls seeing one outside its burrow in the long
grass. The next day, it was still in exactly the same place.
But it was also well and healthy.
Tuatara are adapted to the cold and were widely distributed
throughout New Zealand before habitat change and rats (stoats
and other predatory mammals had not yet arrived) pushed them
off the mainland to a few small offshore islands.
In modern times, tuatara have never been further south than
Cook Strait. The 44 tuatara translocated to Orokonui from
Takapourewa/Stephens Island in October, and therefore are
very special. They are the first free-roaming tuatara on the
South Island mainland for several hundred years. They will be
carefully monitored to see how they grow and reproduce in a
colder climate. A second group of 28 captive-reared tuatara
arrived in November from Nga Manu Nature Reserve at Waikanae
on the Kapiti Coast.
The two welcoming ceremonies underlined just how special
these animals are and how privileged Orokonui is to host
More people attended the first reintroduction ceremony than
almost any other, and Ngati Koata, who are their Nelson-based
kaitiaki (guardians), eloquently conveyed their deep feelings
for the tuatara.
When three of these animals were brought in for show, a hush
fell over the room as they were carried around for people to
see close up.
The feathery crest, the powerful feet and claws, the bright
keen eyes and the unexpected and varied colours of the
tuatara all impressed, but the tuatara had the last say. A
loud warning-like "bark" told the handlers when the show was
• Sue Hensley is head guide at Orokonui Ecosanctuary. Wild
Ways appears in the Magazine section on the first Saturday of