A land of lizards

Sharp-eyes and passion are leading to the discovery of new skink and gecko species in Otago. And the race is on to save them, writes Anna Yeoman.

A single outcrop of solid rock stands in a sweep of scree high above the Maniototo Basin, as lonely as a lighthouse. And weary after a day on the exposed heights of the Hawkdun Range, Tony Jewell turns his well-scuffed boots to descend towards it. Then several metres from the rock he pauses. It is covered in hundreds of flies. He watches them, bemused.

"And then," says Tony, "something truly sublime happened."

Between him and the rock outcrop, a skink poked its head out from the scree. "It was little more than a silhouette from my vantage point, but it was bigger than a McCann’s skink and had a particularly slender, pointy snout," retells Tony. "Right away this ruled out just about every skink species known from these parts."

Then, about a foot behind it, an even bigger head popped out. "It was an adult. And it was big," says Tony. He thought it could possibly be a scree skink, a species known to live in a mountain range nearby. But in that light he couldn’t see the lizard’s colouring.

He took a picture on his cellphone and zoomed in to check if it had the creamy colouring of a scree skink. It was black.

"The cellphone pictures weren’t great quality, so with shaking hands I backed off and took my camera out of my backpack," Tony recalls, "desperately hoping that they wouldn’t bolt." Then creeping closer again he took some photographs.

He was able to get close enough to take photos of the colour patterning and even the scale arrangement. The photographs showed without a doubt that this large gleaming black lizard with fine cream specks was a new species.

This lizard has been named the alpine rock skink. It’s not the only new lizard species discovered recently in the Oteake Conservation Park in Otago. In fact it’s the fourth in the last six years. It’s an incredible statistic. How can we still be discovering new species like this?

In the 1980s we knew of 38 species of native lizards in New Zealand. By 2001 this had grown to 79 species. Late last month the Department of Conservation released the new Conservation Status of New Zealand Reptiles document, detailing 124 lizard species. And many of the new species are in our southern mountains.

"Central Otago appears to be a real hotspot of lizard diversity," says Carey Knox, a Ranfurly-based herpetologist with Wildland Consultants. Late thirties, with short red hair and a friendly grin, Carey knows his lizards.

"Central Otago covers 4% of New Zealand’s land area, but it has 20% of its lizard species. Nowhere else around the country has such a high proportion of species for such a small area," says Carey. At least 25 species of native lizard live in Central Otago.

For a long time we as a country have overlooked our native lizards. We’re so used to being identified as "a land of birds" that our skinks and geckos have slipped under the radar. Most of us don’t realise that in fact we have more species of native lizard than of native land birds.

In fact, New Zealand has a greater diversity of lizards than any other temperate region in the world. By way of comparison, Great Britain, which has a similar land area and climate, has only three. And while we’ve logged 124 species so far, it’s likely we’ve got a good few more.

"I think many people would be a little shocked to learn just how much of New Zealand, and in particular of the South Island, is still poorly if at all explored for lizards," says Tony. "Many mountain ranges have never had a herpetologist set foot in them, and of those that have, only a handful have been really well searched from top to bottom. Perhaps less than a handful."

That’s why people like Tony have been able to find new species at a rate that rivals that of the colonial explorers. With New Zealand lizards, we’re still in the age of discovery.

Three months before the discovery of the alpine rock skink, Tony and Carey were out looking for populations of the Oteake skink, another recently discovered species. They didn’t find them that day, but instead Tony spied the tip of a gecko’s tail disappearing into a rock crevice. Ten seconds later he held the gecko in his hand, and his mind began to spin.

Legs trembling, Tony called out to Carey, "Get up here now! You are not going to believe what’s in my hand!"

It’s another new species. A gecko with olive skin covered in bright flecks of white, like a galaxy of stars. Its eyes are brilliant black, and its lips are golden orange. Carey and Tony describe it as handsome, magnetic. It lives in fractured rock on the ridges of the Oteake mountain ranges, at home in vertical crevices plastered in colourful lichens. It’s been named the hura te ao gecko.

Tony has no formal academic training in herpetology, but he has the peerless record of having helped discover or re-discover at least nine new species of New Zealand lizards. "I may have some good instinct for hunting out critters," Tony admits. "But most of my finds have been stupidly simple, like just turning over a rock. The thing is all of my finds were in areas where the lizard fauna wasn’t all that well explored to start with."

Last year a project was begun to seriously explore our southern mountains for lizards. The "Alpine Data Deficient Lizard Project" is co-ordinated by the Department of Conservation as part of the additional government funding for biodiversity in the 2018 Budget.

Dr Jo Monks, a mother of two with a dark blonde ponytail and a wealth of experience in lizard research, leads the alpine lizard project.

"The project has enabled so much progress that we weren’t making before," says Jo, "because previously we didn’t have a dedicated pot of funding that we could tap into. So it’s been game changing for our knowledge of lizards."

Part of the project is to chase up reports of mysterious lizard sightings in the Southern Alps.

"We follow up on both reports of lizard sightings and lizard footprints in tracking tunnels, especially where they are far from other known lizard populations," says Jo.

The project seems to be off to a good start.

"It’s been amazing!" says Jo. "We’re still desperately awaiting the genetic results to confirm this, but we think we have several new lizard species from that work last summer! It’s so exciting, everyone’s buzzing!" says Jo.

It seems that for those who have the chance to work with lizards, especially those seeking out our elusive, little-known species, there is an addictive excitement to it. When Carey first began working with jewelled geckos for his wildlife management degree, he wasn’t particularly interested in lizards.

"But when I actually went out there and found one in the wild, then I was like, ‘S***, this is the coolest thing ever, why has no-one told me about this!?’," says Carey.

"After seeing the jewelled gecko in the wild I just got hooked straight away — I have a bit of an obsessive personality," he admits with a grin. "It was 2008 when I had my first encounter with a jewelled gecko, and from then it’s just been lizards and that’s it.

"It’s difficult to separate work and hobby because it’s sort of the same for me," says Carey. "Often in the summer when I’m at home in Ranfurly, I’ll just be watching the forecast and trying to see whether it’s going to be a warm night up in the mountains. And if it’s going to be, I jump in the truck and drive up to the top of the range."

It can take two hours of rough four-wheel driving to get there. Carey then spends several hours on top of the mountain range walking around boulder fields shining his torch into the darkness, hoping to see a gecko out and about. On a typical night he might see one or maybe two. Then he sleeps in his tent and drives home in the morning.

Carey and his team have now found 29 hura te ao geckos across six sites.

"We know they’re cryptic, at any one time 90% are going to be out of sight in the boulders and scree," says Carey. Finding them at several sites means that the hura te ao gecko has been able to be listed as "nationally endangered" in the conservation status document, one step below the most acute ranking of "nationally critical".

Yet while it’s a time of great excitement in New Zealand lizard work, it’s also a time of considerable fear. The updated conservation status document identifies more than 90% of New Zealand’s skinks and geckos as "threatened" or "at risk". Only a paltry four species are listed as "not threatened".

Carey and Jo were both contributing authors of the 2021 Conservation Status of New Zealand Reptiles. During a week of intensive meetings, the leading herpetologists in the country discussed how our lizards are faring. They looked at them species by species, drawing on scientific data, observations and professional judgements.

"The big trend across the whole mainland is that things are not so good for lizards, and they’re getting worse," says Jo. "Lizard populations seem to be in decline across most of the country."

Aotearoa used to be alive with the scuttle and gleam of lizards, countless millions of them basking on the rocks and foraging in the shrubs. They filled every ecosystem from the seashore, through the forests and drylands, and up into the alpine zone. Now they’re reduced to small pockets of 30 here, 40 there. Unseen and largely forgotten.

The single greatest threat is predation by introduced pests. Our lizards evolved in a land where their main predators were birds, which hunt by sight. So lizards protect themselves by being visually camouflaged. But mammals hunt by scent, and our lizards have no defence against this. They get slaughtered.

While we’ve identified that removing stoats, rats and possums goes a long way to protecting our birds, it’s not necessarily the case for lizards, which are vulnerable to a wide range of invasive predators.

"Unfortunately, we don’t have good predator control tools for some of the additional predators that are threatening our lizards," says Jo, "like mice, wasps, hedgehogs and cats. That’s what really worries me at the moment. As a country we really have to be investing in understanding these other threats and how to manage them to protect vulnerable lizard populations," says Jo.

Carey agrees. "These are all highly significant predators, and we need to have control methods for all of them. And we need to make sure remaining lizard habitats are protected or restored."

In 1998 a gecko with bright orange spots was discovered on a popular walk near Wanaka. It’s called the orange-spotted gecko, and it’s now been found on six mountain ranges in Central and western Otago, all above an altitude of 1100 metres.

Yet scientists think the orange spotted gecko used to live all across the region, in the lowland forests as well as on the mountain tops. The change came when humans arrived in Otago, burning and clearing much of the lowland forest and introducing pest mammal species. The orange spotted gecko would have been wiped out in the lowlands, while only these small remnants survived on the mountain tops.

This is likely to have been the case for most of the lizard species that we now find only in the alpine zone. Introduced predators haven’t been as numerous in the alpine zone as they have in the lowlands. But with the warming climate, this is now changing. The introduced predators are able to go increasingly high into the mountains, and for longer summer seasons. And as they push up, the lizard species have nowhere else to go.

Jo is hanging out for this summer, when the Alpine Lizard Project can get out in the field again.

"Along the whole length of the Southern Alps we’ve got interesting sightings to chase up on," she says.

She has a spreadsheet of all the leads.

"The next most exciting is a gecko that was seen a couple of summers ago up above 2000m in the Fox Glacier area," says Jo. "It’s one of the highest known lizard records in the country. And based on the photo, the gecko looks totally different, it looks amazing! So that’s top of my list for this summer!"

With over 90% of our unique skinks and geckos threatened or at risk of extinction, it’s time we brought them to the fore of our conservation thinking. It sounds like the first step is to get serious about developing predator control that works for our lizards. The eleventh hour isn’t too late to wake up to our identity as a "land of lizards", as long as we get cracking.

 - Anna Yeoman