Mokomoko
Northern Grass Skink
Oligosoma polychroma
Their Story
These slinky, snake-like lizards are what’s left of Aotearoa’s diverse mainland lizard fauna. While many other species had gone extinct or retreated to the mountains, northern grass skinks, being small, reproducing fast and favouring open grassy habitats, has become the most commonly encountered lizard for most people in Nelson.
Conservation Status
Not Threatened
Northern Grass skinks are one of the few native lizards to be considered not threatened with extinction. While most native lizards have declined to low densities with sparse distributions due to habitat loss and predation, northern grass skinks have expanded their range alongside the increase in grass cover in Aotearoa. This, as well as their short lives and fast breeding, has made these mokomoko resilient to the extreme changes in the ecosystem.
Population
Northern grass skinks are common and reach high densities. Common in native habitats like dunes and alpine grasslands, and in non native habitats like gardens and rank pasture.
Food
Grass skinks, like many day-active skinks, hunt a wide array of invertebrates. They also will eat fruits when available like the fruits of Coprosma and Muehlenbeckia.
Skinks are slender and streamlined. Their heads are relatively narrow and there is not a well defined neck (unlike in geckos). They have narrow clawed fingers. Grass skinks are relatively small and bronze to creamy brown in colour with a darker stripe running along the sides of their bodies.
Skinks are ectotherms, meaning they obtain warmth for daily metabolic requirements from their environment. This results in basking behaviour, or sunning. They have relatively low energy requirements, allowing them to reach high densities in the right habitats. Skinks would have been a common food source for weka, kōtare and even tuatara.
All endemic skinks, with the exception of one species, give birth to live young. Each mother can give birth to up to six offspring in late summer. They typically live for four years, but reach sexual maturity at two years old.
Northern grass skinks is a species distributed across central Aotearoa. They occupy many niches from mountains to sea. Within the forest, they occupy warm edges with dense vegetation and plenty of light. They reach their highest densities in vinelands and grasslands.
Four out of our 143 lizards are not threatened, and the northern grass skink is one of them. They’re small and able to occupy tight spots like the bases of thick grasses, or beneath boulders where they can’t be accessed by rats and mice. Their habitat has grown considerably since the widespread destruction of our forests across the country, which gave way to open grasslands.
Northern grass skinks are a common site along the Sanctuary fenceline. They can also be found in great numbers in the mouse exclosure scrublands. Here there is no mouse predation, which will give other lizard species the chance to recover or be reintroduced.
Skinks, just like other lizards and even tuatara, are capable of dropping their tails when attacked. This is called autotomisation. This is partly why handling lizards without a permit is illegal in New Zealand
Our other residents
Check out some of the other incredible wildlife that call the Sanctuary home
Follow us on Instagram
@brooksanctuary
Share your photos with #brooksanctuary
The soundtrack of a thriving forest 🌿🐦
One of the most powerful things about a pest-free Sanctuary is the sound. With protection from predators, native birds and other wildlife are able to flourish — filling the ngahere (forest) with birdsong from dawn to dusk.
The Sanctuary’s pest-free environment has supported the recovery of native bird populations and the successful reintroduction of species once absent from the region.
From kiwi pukupuku, tuatara, and kākā, to tūī, titipounamu (rifleman), and kererū — the forest is alive once again.
Even the critically endangered kākāriki karaka (orange-fronted parakeet) is thriving here. Following the translocation of more than 120 birds between 2021–2023, the Sanctuary is now home to one of the largest populations in the world, with an estimated 300–400 birds.
Every call, chirp, and rustle is a reminder of what nature can become when given the chance to recover.
🎥Video credit: Hanna Wakeling – captured on a Sunday afternoon from the viewpoint on the Coppermine looking down into the sanctuary
May 25
🍄 A Fantastic Fungi Adventure 🍄
There are still spaces available for our guided Fungi Tours this Saturday at 10:30am and on Wednesday 27 May at Brook Waimārama Sanctuary.
Come and explore the incredible diversity of fungi thriving in the ngahere and discover how these fascinating organisms support the health of the forest ecosystem. Guided by our knowledgeable team, you’ll spot unique species and experience the sanctuary in a whole new way.
Perfect for nature lovers, curious minds, and anyone wanting a deeper connection to Aotearoa’s native environment.
Spaces are limited, so book your Fungi Tour today and step into the world beneath the forest floor.
https://www.brooksanctuary.org.nz/visit/guided-tours-experiences
📷 Photo credit: @chrisbernard1520 recently snapped in the Sanctuary.
May 22
A Fantastic Fungi Adventure 🍄
Come and get your fungi face on at Brook Waimarama Sanctuary!
Join our guided Fungi Tours running in May and explore the incredible diversity of fungi thriving in the ngahere. Learn how these fascinating organisms support the health of the ngahere, spot unique species with knowledgable guides, and experience the sanctuary in a whole new way.
Perfect for nature lovers, curious minds, and anyone wanting a deeper connection to Aotearoa’s native environment.
Spots are limited – book your Fungi Tour today and don’t miss out!
👉 Secure your place now and step into the world beneath the forest floor.
📷Photo credit: Rebecca Bowater
#fungi #nelsontasman #gguidedtour #nature
May 11
Ngā mihi nui to @nbs.co.nz for their support of the Sanctuary.
As a longstanding sponsor, NBS plays an important role in helping us protect and preserve our 690-hectare pest-free Sanctuary for future generations.
Your generosity also helps support local people when they need it most. We’re incredibly grateful for your partnership and commitment to our community.
#bankingforlife #nbscommunity #brookwaimāramasanctuary #nelsontasman
May 10
Sideways roly-poly: kiwi chick edition 🐣
This kiwi pukupuku chick tries a shortcut, takes an almighty tumble, pops straight back up, and, full of determination, makes up the bank the second time.
Our tiny fluff ball is learning some important life lessons.
If this made you smile, share it with someone who needs that energy today.
#kiwi #kiwichick #newzealandwildlife #wildlifeofnewzealand #nznature #naturelovers #conservation #wildlifevideo #cuteanimals #feelgoodvideo #naturevideo #forestfriends #aotearoa #nelsonnz #visitnelson #savethekiwi
May 7
One year ago, something truly special arrived at the Sanctuary — 41 precious kiwi pukupuku ✨
Since then, it’s been an incredible journey. From careful monitoring to those quiet, thrilling moments of discovery, we celebrated our first chicks just before Christmas last year and now estimate that 10–15 have successfully hatched within the Sanctuary. A powerful sign that this tiny, rare kiwi is thriving.
Our night tours have brought visitors closer than ever to these elusive taonga, creating unforgettable experiences and deepening connections to Aotearoa’s unique wildlife.
Every visit, every donation, and every bit of business support help protect not only kiwi pukupuku, but all the species that call the Sanctuary home. Together, we’re building a future where they can continue to grow and flourish in a safe, pest-free environment.
We’re incredibly grateful to our staff, volunteers, and supporters for helping turn this vision into reality.
Here’s to one year of kiwi pukupuku in Whakatū (Nelson) — and many more to come.
🌿✨
📷Photo credit: Sean McGrath
@docgovtnz @nelsoncitycouncil @digitaldiligencenz @nelsontasmannz @nelsonairportnewzealand @savethekiwinz @terunangaotoa
May 6
