Aotea – island of lizards
by Halema Jamieson (Ecologist/Herpetologist)
When we think of reptiles we usually think of warm tropical places like
Australia and the Pacific islands. Remarkably then, New Zealand with a
predominantly temperate climate has over 100 species of native lizard.
Over 75% of these species are considered threatened or at risk. Many
species are now completely absent from the main islands of New Zealand
and confined to offshore islands or mainland sanctuaries.
This drastic decline has been due to habitat destruction and the ongoing
effects of introduced mammalian predators like cats, rats, mice and
High lizard diversity
Today, Aotea Great Barrier is among a few small areas of New Zealand
with a high diversity of native lizards. Despite losing at least three
species and the tuatara (NOT a lizard), the island is still home to an
impressive 13 native lizard species (five gecko and eight skink) (Box
1). Some of these species are extinct on the mainland, and for others,
Aotea Great Barrier is one of only a handful of places where these
animals still exist on the planet. And their future is not secure.
Ongoing predation from cats, pigs and rodents (ship rats, kiore, and
mice) puts constant pressure on remaining populations, and over 85% of
the island’s species are listed in the latest New Zealand Threatened
Everything eats lizards
The sad fact is that everything eats lizards. The presence of introduced
animals plays a large part in their continued survival on Aotea.
Rodents are especially bad and have been implicated in the extermination
of numerous species from large parts of their former ranges. Although
mice, ship rats and kiore are still on Aotea, the largest rat in New
Zealand, the Norway rat is not known to be on the island. Neither are
hedgehog, possum or any of the mustelid family (stoats, weasels,
The introduction of any of these predators would spell disaster for most
of the island’s remaining wildlife (lizards, birds, frogs and bats)2.
...over 85% of the island’s [lizard] species are listed in the latest
New Zealand Threatened Species classifications...
Lizards play an important role in the functioning of native ecosystems.
They are tiny predators eating insects and other invertebrates,
important food for native birds like ruru/morepork and
kotare/kingfisher, pollinators and seed dispersers to many native plants
through their consumption of nectar and fruits. It is vital that they
The continued existence of Aotea’s unique lizard fauna will require
ongoing vigilance, and a commitment to reducing the pressure of
predators on these often forgotten element of New Zealand’s indigenous
fauna. Our native lizards need your help!
(Woodworthia maculata): Known from coastal areas among rocks and
under debris, not as common as it was.
townsi) At Risk: found only on Aotea, Hauturu, Mokohinau/Pokohinau,
Hen and Chickens Islands. Very rare on Aotea, confined to two
small catchments. Named after prominent New Zealand
herpetologist David Towns who lived some of his early years at
pacificus) At Risk – Relict: Widespread throughout the
island, although no longer common.
smithi) At Risk: Still found in limited localised areas on
the mainland. Limited to small coastal areas.
striatum) At Risk-Declining: Very few sightings on Aotea and
extremely rare on the mainland. Likes mature forest with lots of
epiphytes. A very good climber, closest relative is the chevron
skink. Identified by obvious pale stripes down the back.
Aotea’s fabulous native lizards
Photographs: H Jamieson unless stated.
Many lizard species considered to be very rare, or no longer found on
the mainland, can be found on Aotea - some of them are record holders!
New Zealand’s longest lizard— Chevron skink/Niho taniwha (Oligosoma
homolonotum) Nationally Vulnerable: Can be over 30cm long and
characterised by the chevron-like markings down its back and a
‘tear-drop’ pattern under each eye. Extinct on the mainland and now
found only on Aotea and Hauturu (Little Barrier Island). With almost
mythical qualities, is best known from Aotea where they are often
brought in by cats, or found squashed on the road.
New Zealand’s largest gecko and one of the largest geckos in the world –
Duvaucel’s gecko (Hoplodactylus
duvaucelii) At Risk – Relict: Very rare on Aotea, this species was
not seen for around 40 years until recently found near Windy Hill
Sanctuary, Tryphena. Confined to predator-free islands or mainland
sanctuaries, Duvaucel’s gecko does not survive with rats.
Forest gecko (Mokopirirakau
granulatus) At Risk – Declining: Not often seen although still
hanging on in forest areas where rats are controlled. Used to be common
on the mainland.
moco) At Risk: Very rare on the mainland and mostly confined to
islands. Does not do well in the presence of rats or cats.
Ornate skink (Oligosoma
ornatum) At Risk-Declining: Found on Aotea amongst leaf litter and
often brought inside by cats. Confused with the chevron skink.
Auckland green gecko/elegant gecko (Naultinus
elegans) At Risk – Declining: Bright green like Kermit the frog. Very
rare on Aotea with very few sightings in the last 20 years. Was once
common in Auckland.
aeneum): Most commonly encountered skink on Aotea but not as common
as it used to be. Often brought inside by cats.
Egg laying skink/Suter’s skink
suteri) At Risk: Very rare to absent on the mainland. Very rare on
Aotea. New Zealand’s only egg-laying lizard. Does not survive well in
the presence of rats.
R., Barr, B., Lettink, M., Monks, J., Reardon, J., Tocher, M., van
Winkel, D., and Rolfe, J., 2016. Conservation status of New Zealand
reptiles, 2015. New Zealand Department of Conservation.
Biosecurity will remain a critical issue for Aotea, not just for
introduced predators such as Norway rats and mustelids. An accidental
introduction to Tryphena of the invasive Australian plague skink is
likely to displace and outcompete several native lizards , placing more
pressure on declining populations.
Environmental News Issue 38