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Story and photos Jan Power
Skinks and geckos are all lizards — and New Zealand has more than 130 species of lizard. If that sounds a lot, it is; for our land area we have the highest diversity of lizards of any country in the world.
They arrived in New Zealand millions of years ago and diversified. Sixty percent of New Zealand’s lizards are skinks all belonging to one genus, but within the geckos there are seven genera.
Those are just some of the fascinating facts that we who attended EBSP’s AGM learned from our guest speaker, consultant herpetologist (aka lizard expert) Nick Harker, president of the New Zealand Herpetological Society.
Nick shared some tips on how to tell a skink from a gecko. Broadly speaking, skinks are the elegant catwalk models of the lizard community: they are slim — like snakes with legs and long, slender toes. Think slinky skinks. On the other hand, geckos are lizards with attitude. They have “distinct” heads on short necks, “robust” limbs and fat toes. Under their relatively stout toes, geckos have modified scales that help them stick to walls. Skinks blink (another rhyming mnemonic). Geckos don’t. Which is why geckos confront humans they encounter with a fixed, unblinking gaze. These two broad physical categories can help the average bush walker take an educated guess at whether they’re looking at a skink or a gecko. But, such sweeping generalisations do both skinks and geckos a grave injustice because, Nick told us, “every lizard has a unique pattern that distinguishes it from all other lizards”. You can use photo ID to identify a lizard, and if you see that same lizard 10 years later you can use its photo ID to identify it again. And that pattern will hold true throughout its life, despite shedding skins.
Some unique features of Aotearoa’s lizards are that because of our relatively cold climate, they give birth to live young and have a slow life history. Some take 10 years to reach maturity and breed only biennially. Many species are known to live for 50 years. And no, the Tuatara is not a lizard, although, like lizards, it is a reptile.
The role of lizards in the environment is to be pollinators, seed dispersed, predators of invertebrates, and scavengers. More than 80% of New Zealand’s lizards are at risk or threatened with extinction, mainly because of terrestrial invasive predators. They evolved with bird predators, relying on camouflage to hide. But staying still and blending in with their surroundings is of no use if the predators they now deal with (mammals) rely on smell to find them, especially at night. Large lizards, especially, are too big to hide, like McGregor’s Skink, the Robust Skink, Duvaucel’s Gecko and the Chevron Skink. Of these, Duvaucel’s Gecko and the Chevron Skink are still present on Great Barrier Island, but the other two are only on islands with no mammalian predators. In addition to four-legged predators, some lizards — especially stunningly beautiful specimens like the Green Gecko (Northland) and the Jewelled Gecko (South Island) — are poached by human predators for the international pet trade.
Historically, up to 20 species of native lizards and the Tuatara occurred on the Auckland mainland. Of these, seven are now restricted entirely to islands and five are regionally extinct. One Auckland endemic species was recently recognised — the Korowai Gecko. But while all these native lizards are finding it tough going to survive, at least on the mainland, the introduced Rainbow Skink (called the Delicate Garden Skink in Australia, where it comes from, and referred to as the Plague Skink in New Zealand, where it was introduced accidentally in the 1960s) is thriving, and it breeds so prolifically that it reaches plague proportions here.
Geckos are not commonly found in gardens. But, if you live near some native bush, you may encounter three species of gecko: the Forest Gecko, Elegant Gecko (bright green), and the Pacific Gecko. If you live near Muriwai, you may even come across our Auckland-endemic species the Korowai Gecko. Skinks you might encounter in your garden (in addition to lots of Rainbow/Plague Skinks) include the Copper Skink and Ornate skink. Other species include the Shore Skink, Striped Skink (very rare; they live in the tops of trees), and Moko Skink - which used to be common around Auckland but is now found only on the Whangaparaoa Peninsula or on pest-free islands. To make your garden lizard-friendly, Nick advises encouraging them with rocks and rotten wood. Plant native species. Geckos like kānuka and red matipo. For skinks, plant flax, muehlenbeckia and renga renga. His final piece of advice: “Keep cats indoors. They eat a lot of lizards.”
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Captions: Nick and some of his lizard friends came to our AGM.
Set 1. Nick is pictured holding a robust skink (Oligosoma alani). - NZ's largest
species of skink
Set 2. Michelle and others holding an elegant gecko (Naultinus elegans)
Set 3. Margaret Voyce and others with a Duvaucel's gecko (Hoplodactylus duvaucelii) - NZ's largest species of
gecko
Set 4. Forest gecko (Mokopirirakau granulatus)
All of them are local species. The elegant gecko and forest gecko can still be
found in forest/scrub on mainland Auckland, whereas the Duvaucel's gecko
and robust skink would have previously occurred around Auckland, but are
both extinct on the mainland (only survive on islands).
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