Creating a Home for the Southern Grass Skink
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As part of our ongoing commitment to restoring biodiversity across the Pūharakekenui catchment, the Styx Living Laboratory Trust has been working on a unique project to support one of Canterbury’s small but resilient native reptiles — the Southern Grass Skink (Oligosoma polychroma). This project marks an exciting step in strengthening local species populations and demonstrates how targeted habitat creation can help wildlife thrive alongside a rapidly changing landscape.
Why Southern Grass Skinks Matter
Southern grass skinks are widespread throughout Canterbury and Otago, with their northernmost range brushing the outskirts of Christchurch. You may spot them basking on rocks or darting through dry grasses, their swift movements often giving them away before you see their slender bodies.
As ectotherms, these skinks depend on the warmth of the sun to regulate their body temperature. This makes them especially vulnerable to habitat loss or modification, as the availability of warm, open patches can determine whether a population survives.
While not currently classed as threatened, their habitat is fragmented, and development can easily displace entire local populations. Ensuring suitable, connected habitat is essential for long-term population stability — especially in a catchment undergoing rapid change.
A New Home in the Pūharakekenui
In early 2025, SLLT’s field team was contracted to create a dedicated lizard habitat in the lower Styx catchment. This site will serve as a safe relocation area for skinks that currently live on a neighbouring property being prepared for development.
The team designed the habitat to replicate the natural conditions skinks rely on:
- Sun-drenched basking sites made from warm rocks and logs
- Complex vegetation layers, providing shelter, cover from predators, and hunting opportunities
- Microhabitats that offer both cool refuges and warm, exposed areas
- Safe movement corridors, allowing the skinks to disperse naturally across the site
- Ground stability and texture, mimicking the rough, varied surfaces that these agile lizards prefer
Thanks to the field crew’s efforts, the new habitat is fully established and ready to receive the translocated animals when the time comes.
Science-Based Habitat Creation
Designing lizard habitat is more than placing rocks and plants — it requires understanding the behaviour and physiology of the species.
Southern grass skinks need:
- High exposure to sun to maintain preferred body temperatures
- Dense ground-level vegetation to escape predators
- Small cavities and refuges for shelter during temperature extremes
- Edge environments where grasses meet open patches, supporting both foraging and safety
By weaving these elements together, the team has created a mosaic of micro-environments that will allow the skinks to thermoregulate, feed, shelter, and breed in the years ahead.
Monitoring the Move
Once the skinks have been carefully relocated to their new home, SLLT will support ongoing population monitoring to assess:
- how successfully the skinks establish themselves
- dispersal patterns from the release site
- long-term survival rates
- interactions with predators or competitive species
- how the restored habitat develops over time
This information will help guide future translocation and habitat restoration work across the catchment.
A Small Lizard With a Big Role
Healthy skink populations indicate healthy groundcover ecosystems. They help control insect numbers, contribute to nutrient cycling, and provide food for native predators such as kārearea and pōpokatea.
Supporting species like the Southern Grass Skink contributes to a wider ecological vision — a diverse, resilient Pūharakekenui landscape where native species can flourish.
