Turning the tide for tarapirohe/black-fronted terns
One of the most threatened braided river birds in Waitaha Canterbury is getting a lifeline thanks to a united push to protect its fragile braided river habitat.
In a collaborative effort to protect the tarapirohe/black-fronted tern, we are working alongside the Department of Conservation (DOC), Land Information New Zealand (LINZ), and Ngāti Kuri to restore and enhance its habitat in the Upper Waiau Toa/Clarence River.
Tarapirohe are entirely dependent on braided rivers for nesting, and Waitaha is estimated to host around two-thirds of their national breeding habitat. The Upper Waiau Toa and the Wakaputawatea/Acheron River together supported an estimated 630 breeding pairs during the 2024/25 season, making this a nationally significant site for the species.
Turning river islands into safe havens
Over the past year, the project has focused on giving nesting birds a better chance at raising their chicks. The team worked on selected river islands, carrying out targeted habitat improvements like:
- improved selected river islands by clearing weeds
- raising the ground, providing less flood-prone areas that are free from predators
- carving out clear channels, making them safer and more attractive for nesting
- added shelters to protect vulnerable chicks
- increasing predator control to safeguard breeding success.
“To give tarapirohe the best chance at survival, we needed to create safe, high-quality nesting habitats where they could raise their young with minimal disturbance,” said Frances Schmechel, our principal biodiversity advisor.
Islands in braided rivers are the safest place for tarapirohe chicks
“Enhancing islands to provide secure and consistent nesting spaces has proven to be one of the most effective actions we can take. Every weed cleared and every island improved is a meaningful step toward securing their future,” she said.
To measure the impact of these efforts, the team tracked breeding results at both managed and unmanaged sites. This helped them understand how much of the success was due to habitat improvements, and how much was influenced by natural challenges like floods or bad weather.
Early wins for tarapirohe
Monitoring showed that birds nesting on river islands had much better hatching rates than those on the mainland. Cameras revealed that predators were more active on mainland sites or on islands that became connected to the mainland when water channels dried up. This highlights how crucial it is to keep nesting areas isolated and protected. To track breeding success, the team looked at several key indicators:
- Hatching success – how many chicks hatched from the eggs laid
- Nesting success – how many nests hatched at least one chick
- Fledging success – how many chicks survived to the flying stage per nest
- Adult numbers – how many adult birds and breeding pairs were present over time
Isolated islands protect tarapirohe from ground predators
Looking ahead to the future
Now in its fifth year, the project is approaching the end of its initial trial phase.
Insights from the trial are already informing braided river habitat restoration across the region. Successful interventions such as adding chick shelters are being adopted more widely and shared with others in the conservation community, including at the annual BRaid conference.
Ultimately, the goal is to determine which actions make the biggest difference for the investment — especially in braided river ecosystems, which are naturally unpredictable and need long-term data to guide smart decisions.
By expanding and refining our efforts through these long-term trials, the more we learn, the better we can protect these special birds.