Rise in fernbird numbers a sign conservation work paying off
The number of rare native fernbirds in the Waimea Inlet is on the rise in a sign that that a community conservation project is making an impact.
A fernbird survey this year by the Battle of the Banded Rail group found at least eight of the secretive fernbirds in the inlet, compared to only one seen in a 2018 survey. The surveys visited the same 20 potential fernbird habitats, using amplified calls to attract the long-tailed, well camouflaged birds that live in tangled shrubs on estuary margins.
Fernbirds or mātāta are rare in the Nelson Tasman region, with small populations found in Golden Bay, Wakapuaka and Mārahau. Nationally, they are classed as at risk-declining.
Even more encouraging for the conservation group, which is supported by the Tasman Environmental Trust, was the sighting a week after the survey’s completion of two adults and a juvenile at one of the inlet sites, indicating a successful breeding pair.
Battle for the Banded Rail project manager Kathryn Brownlie said the results were very heartening, providing more confidence that the group’s pest trapping and habitat restoration was working. The group was formed in 2015 after habitat loss from development around the inlet margins and predators caused a marked decline of native bird species, including fernbirds and the even more reclusive banded rail.
Since then, with the help of community volunteers, it has trapped more than 11,000 predators, largely rats and hedgehogs, but also 600 stoats and weasels that can wreak havoc on bird populations.
Around 164,000 plants, including rushes and flaxes, have been planted in the inlet and its margins, half by community volunteers who will begin the 10th year of winter planting next month. Funding from the One Billion Trees programme also provided a planting boost.
In the February survey, fernbirds were seen at three different sites in the inlet: five at Manuka Island, one at the Waimea delta, and two at Pearl Creek.
The survey also revealed increased numbers of other birds. Sightings of the extremely shy banded rail increased from zero in 2018, to sightings at five different locations. Banded rail are so reclusive, they can usually only be detected through their footprints.
Black-fronted tern and royal spoonbills were found at four locations, compared to only one in the previous survey, and the total number of bird species found in the inlet increased from 43 in 2018 to 50 in 2024.
The new species seen included weka, eurasian coots and Australian wood ducks.
Battle for the Banded Rail trapping co-ordinator Tracey Murray said the group was extremely pleased to see fernbirds numbers increase, and evidence of successful breeding.
“What a difference habitat restoration and predator control makes to the survival of these precious birds.”
Murray said fernbirds and banded rails needed good water quality and plants to thrive, so their presence in the inlet indicated a healthy wetland. She said the next targeted banded rail survey would be carried out in October-November this year.
The conservation group thanked the Birds NZ members who helped with the surveys, as well as all the volunteers involved in the trapping and planting programme. More volunteers were always welcome, and could get in touch by emailing bandedrail@gmail.com