About 160 captive-raised critically endangered kakī have been released into the wild, capping off another successful breeding season according to the Department of Conservation.
In 2023, the total wild adult population nationally were estimated to be close to 169. This number fluctuates but is said to be trending up.
The recent season saw the highest number of breeding pairs in the wild from 17 pairs 10 years ago to 41 pairs today.
DoC Twizel senior biodiversity ranger Dean Nelson said it was a positive season but the kakī were still vulnerable.
“They are still doing it tough in the wild as they are vulnerable to introduced predators. On average, about 30 per cent of released birds survive to adulthood.”
The black stilts were raised in captivity through the Kakī Recovery Programme, which is trying to bolster the wild population of the critically endangered taonga species.
About 80 birds were released at Lake Tekapo/Takapō and another 78 into the Tasman Valley
The programme’s Ngāi Tahu representative, Rynee de Garnham, said the newly released kakī were going to face many challenges in the wild, after being in captivity their whole life.
“So much of their new environment is unfamiliar to the manu including navigating frozen water and interacting with other bird species they have never encountered before.
“While the mortality rate remains high, it is encouraging we have been able to preserve the whakapapa of the kakī to help increase their chances of withstanding threats from disease,” said Garnham.
Nelson explained that the birds were reared at DoC’s Twizel kakī facility and The Isaac Conservation and Wildlife Trust in Christchurch.
“Staff will provide the newly released sub-adult kakī with supplementary feeding for up to six weeks to help them settle into their new environment while they are learning to fend for themselves.
“Two more birds are being treated for bumblefoot/ulcerative pododermatitis at the Wildlife Hospital, Dunedin, and will hopefully be fully recovered and fit for release soon.
“We’re also retaining eight young kakī in captivity and it’s hoped they will become future captive breeders. They have been selected to retain maximum genetic diversity in the captive population.”
Nelson said the programme’s next goal was to create methods to increase the survival rate of the taonga species by understanding the causes of mortality.