One of New Zealand’s most secretive and least understood reptiles is finally giving up its secrets, after researchers fitted dozens of tiny radio backpacks to a population of northern striped geckos hidden away in the forests of the Coromandel Peninsula.
The northern striped gecko is so cryptic that scientists did not even recognise it as a distinct animal until 1997, and it was only formally described as its own species in 2020 by researchers Hitchmough, Nielsen and Bauer in the journal Zootaxa. Classified by the Department of Conservation as Threatened and Nationally Vulnerable, the gecko is known from only a handful of sites on the Coromandel, and much of its life has remained a complete mystery.
That is starting to change. Working at the Mahakirau Forest Sanctuary, University of Otago zoologist Dr Jo Monks and masters student Harriet Wills spent the past few months attaching miniature radio transmitters to the geckos and following their movements day and night, as RNZ reported.
Each transmitter weighs less than 0.63 grams and sits inside what looks like a tiny backpack, wrapped against the gecko’s body with self-adhesive tape to form a small harness. The devices are light enough that they do not restrict the animals as they climb and forage, which matters a great deal for a creature that spends much of its life clinging to thin branches in the dark.
For an animal that has evolved to be almost impossible to find, the work was painstaking. “They camouflage extremely well with their environment,” Dr Monks told RNZ. The geckos are masters of disappearing into the bush, and tracking them by eye alone is close to hopeless, which is exactly why the radio tags have proved so valuable.
“The goal was to really try and figure out objectively how these elusive northern striped geckos are using habitat,” Dr Monks said. Rather than guessing from the few chance sightings recorded over the years, the team could now follow individual geckos and build a real picture of where they go and why.
The findings have already overturned some assumptions. The geckos turned out to favour the edge of the forest, living among low shrubs such as gorse and manuka rather than deep in the canopy at all times. During the day, when they are near a forest edge, the geckos tuck themselves under leaf litter and stay out of sight. When they move further into the forest, they climb higher and spend more time in the canopy, most likely to soak up the warmth of the sun.
That behaviour helps explain why the species has been so hard to study, and it also hints at something hopeful. The tracking suggests the gecko may be more widely distributed across the Coromandel than the small number of known records would imply. “Particularly the extent of their distribution is one of the remaining mysteries,” Dr Monks said.
Knowing where the geckos actually live, and what kind of vegetation they rely on, gives conservation managers something concrete to work with. If the animals depend on scrubby forest edges and shrubland that is often dismissed as low value, then protecting that habitat becomes part of the job rather than an afterthought.
The northern striped gecko is a striking little animal once you get a good look at one, which is rare in itself. It grows to a snout to vent length of up to 95 millimetres, with a tail longer than its body. Its back is light to dark tan, broken by wide pale stripes, and it has a distinctive mouth with a pink lining and tongue and a flash of orange at the corners. Like most native New Zealand geckos, it feeds on a mix of invertebrates and nectar, and in captivity the species has been seen taking winged insects such as lacewings and dobsonflies along with fruit.
The research at Mahakirau is the product of a long collaboration. The sanctuary covers around 600 hectares and is looked after by the Mahakirau Forest Society, whose volunteers have run predator control across the site since 2016 to give native wildlife a fighting chance against rats, stoats and possums. Auckland Zoo has been a key research partner, and earlier groundwork on the project was begun by researchers at Massey University. According to Auckland Zoo, more than 150 individual geckos have now been identified at Mahakirau, thought to represent around 85 percent of the entire known population of the species.
That concentration is a double edged thing. It means the sanctuary is doing extraordinary work, but it also underlines how precarious the gecko’s situation is. A species where most of the known animals live in one valley has very little margin for error, and a single bad year of predators or fire could be devastating. Sustained pest control and a better understanding of where else the geckos might be hanging on are the two things most likely to keep the species safe.
For now, the little radio backpacks are quietly doing their job, beaming back the daily habits of an animal that has spent millions of years perfecting the art of not being seen. Each location fix is another small piece of a puzzle that conservationists have barely begun to assemble, and a reminder that even in a country as well explored as New Zealand, there are still wild secrets tucked away in the bush waiting to be found.
What do you think of the work being done to protect New Zealand’s rarest native species? Have you ever spotted a gecko or other native lizard in the wild? Share your thoughts in the comments below.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂
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