New Zealand's wild kakī/black stilt population has been boosted with the release of 148 young birds in Te Manahuna/Mackenzie Basin this month.
Kakī are one of New Zealand's rarest native wading birds and a taonga species for Ngāi Tahu. Conservation efforts over the past 40 years have seen this striking wader – known for its distinctive black plumage and red legs – rescued from a low of just 23 birds and the brink of extinction.
The released kakī were raised in captivity by the Department of Conservation (DOC) at their Twizel kakī facility, and by The Isaac Conservation and Wildlife Trust in Christchurch. They join an estimated 141 adult birds in the wild, whose population fluctuates but is slowly increasing.
This month, 75 kakī were released at Lake Tekapo/Takapō, and another 73 into the Tasman valley, where extensive trapping helps protect the birds from introduced predators like stoats and feral cats.
DOC Senior Biodiversity Ranger Dean Nelson says the annual kakī release is a highlight for the local community, and the culmination of ten months of intense work.
"Each young kakī released into the wild has been hatched from incubated eggs taken from wild or captive pairs, then fed and cared for in captive facilities over many months," says Dean. "For the teams that raised these birds, it's a very special time, and a great feeling to set them free and watch them fly unrestricted for the first time.
"Kakī are critically endangered and found only in New Zealand. Our efforts to bolster and protect the wild population in the Mackenzie are crucial to their survival."
The newly released kakī will be given supplementary food for up to six weeks as they settle into their new environment. Meanwhile, the DOC kakī team will clean and disinfect the kakī incubators and hand rearing facilities in preparation for springtime, when egg collection and incubation will start all over again.
Despite the extensive predator control across the braided river habitat in the Tasman, Godley, and Cass valleys, kakī are vulnerable in the wild. On average, about 30 per cent of released birds survive to adulthood.
Dean says planned research, funded from the International Visitor Conservation and Tourism Levy, will use solar-powered GPS transmitters on kakī to improve understanding of why so many young birds are lost, and better focus management activities.
"We plan to use the GPS tags on young birds released next season and track them for up to a year. We'll see where they go and what threats they face in different parts of the Mackenzie basin, where they live year-round."
Trials are already underway with captive kakī to find the best method to attach the transmitters to the birds. This work was sponsored by Environment Canterbury and Guide Hill Station.
Extensive trapping takes place across the Mackenzie Basin, including through Te Manahuna Aoraki and Project River Recovery programmes, with vital support from local landowners.
Support from partner organisations is crucial to kakī conservation efforts. The Isaac Conservation and Wildlife Trust raises birds at its captive breeding facility in Christchurch, continuing Isaac Construction founders Sir Neil and Lady Isaac's vision to give back to nature. This year, the trust contributed 55 kakī for release.
Background information
Funding from the International Visitor Conservation and Tourism Levy of $700k for the Kakī Recovery Programme over next three years will support a range of projects. These include trapping in key kakī breeding and feeding areas in the Godley and Cass rivers, GPS tracking research, improvement of biosecurity measures at the Twizel kakī captive facility and enhancement of ponds at Micks Lagoon and Mailbox Inlet used by kakī for feeding.
Visitors to the Mackenzie can play their part by giving kakī space especially in the nesting season from August to January, keeping their dogs under close control, and not driving in riverbeds.
A Study in Conservation - Isaac Conservation & Wildlife Trust
