The annual flock count at beaches in Southland last week revealed the dotterel population has grown from 105 in April last year to an estimated 160.
This is the biggest annual increase for dotterel since recovery efforts began over 32 years ago.
Department of Conservation (Doc) Rakiura operations manager Jennifer Ross said in a statement it was a huge boost for everyone supporting the critically endangered shorebird.
"After years of small gains, and more commonly, devastating losses, this is the result we needed to help save pukunui from extinction."
An aerial predator control operation by Doc and Zero Invasive Predators in winter made the difference, showing how vital 1080 was in the conservation tool kit alongside traps and bait stations, Ms Ross said.
"We managed to reduce feral cats to very low levels in the operational area.
"This protected adult birds while they nested and raised their chicks on the mountain tops.
"The timing was critical as the pukunui population had rapidly declined from 176 in 2020 to 105 in 2025."
Ninety-one out of 97 previously known adult birds survived along with 56 newly banded juveniles, one new adult and five unbanded birds.
As done in previous years, 5% is added to account for other birds that were not present during the count.
"In recent years, we’ve lost up to 40-50 adult birds to feral cat predation.
"Males are particularly vulnerable as they incubate the eggs overnight when feral cats are more active.
"A lot more birds have been able to pair up this season and in some cases, they’ve hatched three chicks in one clutch."
It was an incredible result, however dotterel were still far from safe, Dean Whaanga, a member of the Ngāi Tahu leadership group involved in Predator Free Rakiura, said.
Trail cameras detected feral cats at the edges of the operational area and they were present at breeding sites elsewhere on the island.
"It’s critical we continue to take action, not just for pukunui, but to uplift the mauri of Rakiura and enable other taonga species like kākāpō and tīeke to safely return," Mr Whaanga said.
While feral cats remained on the island, dotterel would always be under threat, Ms Ross said.
"Until we can eradicate feral cats and other predators from Rakiura, we will have to hold the line using the best predator control tools at our disposal."
While no aerial predator control operation is planned on Rakiura this year, feral cats will continue to be closely monitored.
"The big question is how long it will take feral cats to reinvade pukunui breeding sites in the operational area," she said. — Allied Media
