Kākā chicks have hatched, and successfully fledged, for the first time at Abel Tasman National Park.
Until recently the native parrot has been considered "technically extinct" in the Abel Tasman where only a few wild male kākā remained.
The Department of Conservation (DOC) and a private group Project Janszoon began releasing captive raised females four years ago into the park.
Project Janszoon director Bruce Vander Lee said monitoring had shown one pair have successfully had four chicks that recently fledged.
"A captive raised female has not only survived in the wild but found a wild male and successfully bred," he said.
"We are especially pleased the wild male has been able to contribute his genes to the population. Two kākā have become six, it's the first step to a kākā population recovery in the Abel Tasman.
"We have been monitoring them regularly and they have all successfully fledged and been seen flying."
Nearly 95 percent of the park is stoat trapped, and the nest was found on the edge of an area which has had aerial predator control using 1080, Mr Vander Lee said.
Additional measures were also taken to protect the chicks with a section of the tree being wrapped in slippery, heavy duty plastic to make it harder for predators to climb the trunk to the nest.
DOC and Project Janszoon are hoping to release as many as 25 more kākā in the area this year.
The birds have been taken as week-old chicks or eggs from nests at Nelson Lakes and Kahurangi National Parks over summer and are currently being raised by captive-breeders.
All of the wild pairs whose eggs were taken for the project have since been re-nested.