Many of our skinks and geckos are so new to science that they don’t even have names. Much of what we do know about our lizards is thanks to an amateur herpetologist from Invercargill with no academic training.
I am sitting perfectly still, waiting for my senses to return. Nothing else moves, not even the air. The heat rising from the scree makes the view scintillate, like oil on water. The air is so hot, so heavy, that the tussock butterflies must scull through it.
I’m trying to be the lizard I’m seeking—the alpine rock skink—but I’m distracted by grasshoppers and a pair of capering pipits. I notice a tussock butterfly alight between my boots. There is a blur, and a millisecond later the butterfly is dying in the chomping jaws of a McCann’s skink, its brown-striped body flashing past.
Alpine rock skinks are larger and darker, but since I’ve never laid eyes on one in real life I’m at a disadvantage—my brain has no identikit to go on. So I do whatever Tony Jewell does, which appears to be nothing. He stands motionless, squinting into the glare like a gunslinger. Few know how to look for lizards—how to see lizards—like Jewell does. The scientific literature is very clear about that. Over the last four decades, he has discovered, or rediscovered, 18 new species of skink and gecko in New Zealand.
I fancy that he channels a lizard himself. He thinks what it might be thinking, goes where it would go.
“I think we should give up,” he announces, picking up a rock. “Feel that. It’s too hot now. The skinks have no reason to be out in this.”
He’s right. Even the flies have gone off to find whatever passes for shade in the North Otago summer. “The skinks will be under the stones now, hunting spiders and cockroaches.”
Through semaphore, he summons the other searchers: Carey Knox, Trent Bell, Jacqui Wairepo and Cameron Thorp, all from Wildlands Consultants, and Seth Garden and Nick Reynolds from Auckland Zoo. Before we retreat to our camp, high in the Oteake Conservation Park, Jewell and Knox place a few pitfall traps—an elaborate term for ice-cream tubs set into the scree and baited with tinned pears.
It’s cooler back at camp, where a southerly breaks over the ridge, washing shadows of cumulus across the dun hills. I reach for a jacket, and it strikes me that life at 1400 metres above sea level must be hard for creatures that cannot do the same. Since a lizard can’t manufacture its own warmth, it can only assume the temperature of its place. If it needs to warm up, it must bask in the sun. When it gets too hot, it must seek shade.
This costs autonomy, but it does have some advantages: we humans use at least half of all our energy just maintaining the right operating temperature for our organs.
Food, for us, is a time-consuming preoccupation. Lizards, on the other hand, have much lower energy demands, which means they can go for days without food.
Jewell discovered the alpine rock skink a few years ago, and we know next to nothing about it. It doesn’t even have a proper name. It’s been assigned a genus, Oligosoma, simply because all New Zealand skinks belong to Oligosoma by default. This team is here to give it a second name, but first they must catch one. Then they must kill it.
Scientific convention dictates that, before you can describe and name a new species, you must first submit a specimen, called a holotype. Taxonomists will pore over it, noting features anatomical and genetic that might confirm it as unique. The description and name they give the creature will then be tied to that first sample, which will be held for posterity in a museum somewhere, so that other herpetologists can use it as a reference.
Before that happens, though, the team wants to get some good close-up photographs, particularly of the creature’s scales, an important diagnostic trait. “Maybe we’ll get a tail,” says Knox, “so we can at least do the DNA.”
The alpine rock skink isn’t alone in its obscurity. Of the 100 lizards in the country that we know about, around half of them have no second name. We’re discovering them faster than we can categorise them. When I was a nipper, I could count all our lizards on my hands. In 1967, Sheila Natusch’s Animals of New Zealand rattled through five species of gecko and three skinks in a page and a half, but since the 1990s a couple of new species have turned up every year or so.
“Historically, New Zealand has been very poorly explored for reptiles,” says Jewell. “We’ve got huge areas of mountainous country that haven’t been adequately searched.”
Arguably, nobody’s done more to fix that than Jewell himself. In 1996, he found his first new species, the Takitimu gecko, high in its eponymous mountain range, and wrote its scientific description. In 2004, he and herpetologist Mandy Tocher found the Sinbad skink in Fiordland’s forbidding Sinbad Gully. In 2007, he found the Rangitata pygmy gecko with photographer Rod Morris, who initially thought the geckos they’d uncovered were the babies of bigger ones under the same rock. Jewell demonstrated that one of them was pregnant, and another new species was added to the register. In 2014, he turned over a rock near the Homer Tunnel to discover the Awakopaka skink. Here in the ranges of North Otago alone, he’s discovered a new gecko and three new skinks.
“I’ve been chasing these animals since I was a small kid,” he tells me. “The more time you spend in the field with them, the better you come to know them. That’s how you get the eye for detail.
“In the field, it’s the little things which can tip you off that something different is going on—you notice quite distinctive behaviours.”
While Jewell was surveying the Hawkdun Range in 2011, he noticed a skink, nondescript, like a dozen others. Except that it did an odd thing: when disturbed, it would jump between rocks. “I’d never seen other species do that.”
He caught one and, just like that, the rockhopper skink got its name.
Jewell’s contribution to herpetology would be impressive if he were on the science payroll. But he isn’t. He works at an industrial laundromat in Invercargill. He has no formal training in biology, and has made the overwhelming bulk of his discoveries in his spare time and out of his own pocket.
“I don’t think university would have added much to what I do as a field worker,” he says. “What I do is largely intuitive. I’m basically trained through long practical experience instead.”
That didn’t always sit comfortably with the herpetological orthodoxy—there have been testy exchanges through the letters pages of scientific journals—but science has long since acknowledged Jewell’s bona fides, and he’s published a number of papers describing new species.
However, he says, “I’d be pretty useless at something like a long-term systematic study of a single population. That’s where you need your academic training. But, if you want to know which lizards might be living in an unsurveyed mountain range, you want someone like me or Carey [Knox]—people who pursue it as an absolute passion, rather than employment.”
It’s now 3pm and, though it doesn’t feel any cooler to me, Knox can’t wait to get back down to the survey site. “I just brim with excitement,” he tells me, as I struggle to keep pace with him over the tussocks. “I just want to get back down there and see the animals.”
I urge him to go ahead without me. By the time I crest the nearest ridge, he’s already in the basin, checking his pitfall traps.
Inside one is our quarry: an alpine rock skink. I was expecting its body to be black, but it’s aglitter with gold flecks, an explosion of fractals. Its lithe form is a reflection of place and time—inky one instant, then the next, as a cloud might pass, a warm bronze or washed russet. Above lemon-yellow lips, an eye that somehow expresses comprehension despite a pitch-black pupil. Its long, delicate toes are exquisitely engineered. Knox holds a ruler to the lizard’s tail—78 millimetres—then its body. Knox places it gently into a white box to be photographed. It’s a young female. Since it’s a juvenile, not an adult, it won’t become this species’ holotype.
Another trap holds a green skink, and as Jacqui Wairepo holds it out to me, I see that it’s anything but green. I can’t decide whether it’s a gorgeous deep bronze dappled with black flecks or the other way around. It’s quite stout for a skink (the lexicon requires me to call it ‘robust’), and it’s perhaps 120 millimetres long. As it warms in Wairepo’s hand, it begins to squirm, and when it turns to the sun I see a slash of metallic emerald along its head. “Some have that green most of the way down their bodies,” says Wairepo.
This is one of the most exasperating things about New Zealand lizards: lots of them look the same but they’re different species, while others look different but they’re the same species. Some of their names hint at a certain frustration with this. Cryptozoicus. Inconspicuum. Polychroma.
“For most people, skinks are those little brown jobs that scamper off when you disturb them in the garden,” Lynn Adams, a senior technical support officer at the Department of Conservation (DOC), tells me later, “and, to be frank, most of our skinks look like that—they’re really difficult to tell apart, and it’s taken me years to be able to see the subtle differences.”
The more we get to know them, the more lizards confound our notion of what a species is. In school, I was taught that a species was something sacrosanct: the largest group in which any two individuals can breed and produce fertile offspring.
“That’s a really old concept,” says Adams, “and it’s totally inappropriate for most New Zealand species.”
That’s because many of our lizards respect no such definitions. Nor do lots of other creatures, leaving us with what’s known as ‘the species problem’. Charles Darwin grappled with it back in 1859—in On the Origin of Species, he wrote, “No one definition has satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species.”
So what is the fundamental unit of taxonomy? Maybe there isn’t one.
Think of those colour swatches from the paint shop that you agonise over when redecorating: the top square might be deep red, the bottom pale pink. Plainly distinct, but connected by the squares in between via a chromatic continuum. Similar, but not the same. Many New Zealand lizards have this type of relationship—and the fact that the green gecko Naultinus manukanus has had its name relitigated nine times since 1955 is testament to the mayhem this causes.
Herpetologists talk about ‘clines’, which in our analogy are those gradient squares on the colour chart. A cline is some trait in a species that weakens or intensifies across its geographical range—such as DNA, morphology or colour pigment. For instance, the starred gecko, Naultinus stellatus, is “a big thing with blotchy marks all over it” in the northern part of its Nelson–Buller range, says DOC science advisor Rod Hitchmough, “but by the time you get to its southern limit, south of Karamea, it’s really slender, often without any markings at all. They look so different that they were long thought to be two different species.”
The advent of DNA sequencing in the 1990s was supposed to settle this once and for all, and it certainly revealed differences that saw the species tally climb. The common gecko, previously known as Hoplodactylus maculatus, is now a complex of 11 taxa with its own brand-new genus, Woodworthia. (‘Taxa’ is a generic term biologists use when they’re not sure they’re talking about clear-cut species, while ‘complex’ allows for the creatures’ relatedness at the same time as acknowledging their differences, even if the boundaries are not clearly defined.)
DNA analysis revolutionised taxonomy, but Jewell and others have criticised the focus on genetic evidence above all else. “A population is a species because it has x amount of ‘genetic’ differentiation, or isn’t a species because that differentiation falls 0.1 micrometre short of this imaginary, inexplicable line drawn in the sand,” Jewell bemoaned in his 2017 memoir, An Explorer in a Land of Herps.
Today, taxonomists refer to at least 26 concepts to help to define a species. In this practice, a taxon is the product not just of its DNA, or its scale counts, or the length of its carpals, but an expression of its habitat preference, diet, behaviour, distribution and individual variability.
The old notion of a species is no help at all. We now know that taxa lie along a sexual continuum from total reproductive isolation (with no interbreeding) to anarchy (panmixis, or unlimited interbreeding). The problem now is that these criteria very often delimit species differently, so at any given point lizards meet the criteria for one species concept or another, while violating others.
“Often, distantly related taxa hybridise freely,” says Hitchmough, “while closely related ones won’t.”
In any event, he points out, the “fertile hybrid” test—which asks whether they’d remain as separate species if they were to come into contact—is valueless in New Zealand.
“These species are either separated geographically, or any habitat where they might’ve met doesn’t exist anymore.”
Rather, the key to differentiating lizards, says Adams, lies in their subtleties. She points to the Chesterfield skink, which lives on the West Coast with the speckled skink. For decades, we thought they were one and the same, until someone noticed that, when picked up, some of these skinks wrapped a clearly prehensile tail around their captor’s fingers.
“Speckled skinks can’t do that. We’ve tried it, and they just fall off your hand,” says Adams. “But Chesterfield skinks can grip your hand surprisingly strongly, so we think they’re arboreal.”
Before we chopped down their coastal forest habitat, Chesterfields would have lived above their speckled kin.
“But now they have to live in grass, just as the speckled skink does. So [Chesterfields] went undetected for a very long time—we didn’t understand they were probably arboreal by preference until 2015. It takes a lot of work and a lot of time to understand these sorts of differences.”
There might be just 150 Chesterfield skinks left. Forty-eight of them are at Auckland Zoo, which took them in after Cyclone Fehi all but destroyed their only known habitat, a single hectare of the West Coast. That might be a parable about the conservation of all our lizards: change is coming at them fast, just as they’re clinging to this world by the last of those beautiful toes. And much of that is down to habitat loss.
“It’s impossible to overstate how serious that’s become for our lizards,” says Jewell. “Everything from the loss of coastal habitat by erosion through to alpine tussock grasslands being over-run by weeds and wilding pines, or being grazed, which removes those vital woody herbs that species depend on. Then there’s the drainage and loss of wetlands. We’re losing habitat everywhere, and that’s a huge challenge for the conservation of lizards.”
Jewell thinks many of the lizards we keep finding in the high country are only there because they have nowhere else to go. Until now, introduced predators mostly prowled the warmer, drier lowlands. But, as temperatures climb, so do they, and Jewell suspects the most destructive predators are the smallest: mice.
“The trouble is that, when the lizards are dormant in winter, the mice are still active. We’ve found Takitimu geckos high in the mountains with large scars that we couldn’t put down to fighting with other geckos. We strongly suspect that mice are simply taking chunks out of them while they’re torpid, and there’s nothing they can do about it—if they’re too cold, they can’t get away.”
In all, we sight around two dozen alpine rock skinks on this trip. All of them are juveniles. The quest for an adult specimen takes the team across to the Hawkdun Range, and there they see around a dozen more, but they’re all youngsters too. Jewell isn’t sure why. Maybe the adults spend high summer foraging under the scree, he suggests, in the shade, until insects on the surface hit peak abundance in early autumn. Photographer Rod Morris, an occasional lizard discoverer himself, says he’s observed juveniles separating themselves from adults of the same species to avoid being eaten by them.
There’s still so much we don’t know, and Jewell feels the weight of urgency. His quest is to see skinks and geckos win recognition—and deliverance—before habitat loss or climate change snuffs them out. All in his spare time.
“Most of my life, I just go to work and do what I have to do to get the bills paid, so I get comparatively little time in the field nowadays,” he says. “When I do get out, it’s pure joy for me. I need that exploration, that freedom that comes with just going off into the hills to see what you can find—going where opportunity takes you. It’s a tremendous contrast to my day-to-day life.”