Rare critically endangered chicks hatch in Christchurch; boost mainland gene pool

Shore plover/tūturuatu chick. Photo / Supplied

Rare chicks from a remote island are hatching in Christchurch after a successful multi-day mission to increase the mainland gene pool.

Shore plover/tūturuatu are a critically threatened shorebird endemic to NZ. They are vulnerable to predation from introduced predators, including rats and cats, and have a global population of around 250.

Twenty-one eggs were collected by DoC and the Isaac Conservation and Wildlife Trust (ICWT) from Rangatira, an offshore predator-free island in the Chathams.

After months of planning, three weeks' work on Rangatira, and an 800km journey by sea, air and land, the precious eggs arrived at ICWT's captive breeding facility in Christchurch on November 28.

The eggs began to hatch last week at ICWT, where they will be raised, eventually boosting genetic diversity in the captive breeding programme and other wild populations.

DoC technical advisor and captive coordinator for the Tūturuatu Recovery Programme, Rose Collen, said the young chicks are mission-critical for the recovery programme and it has been an appropriately complex operation to get them here.

"Finding nests can be a challenge, as tūturuatu are very secretive when it comes to their eggs.

"One bird in the nesting couple keeps a lookout and as soon as someone approaches, they're off their nests. We had to do a 'stake out', hiding behind rocks or bushes to watch them return to the nest so we could spot where they were."

Eggs were then checked to identify those at a stage of development that would be suitable for transferring.

The eggs were collected and transported in a temporary incubator by boat to main Chatham Island, then flown to Christchurch and driven to ICWT.

"Rangatira is home to hundreds of amazing species but is particularly special for shore plover. As well as being their main stronghold – there are about 150 birds here, more than half of the global population.

"It's also the site where the original eggs were taken from to start the captive breeding programme in the early '90s."

ICWT assistant wildlife manager Leigh Percasky took part in the egg selection and transfer and said it was exciting to see the chicks beginning to hatch.

"The population on the Chathams is more genetically diverse than the population on the mainland because the last egg translocation happened so long ago.

"These chicks will allow us to breed more robust birds, which we hope will be less susceptible to diseases and create more viable breeding options for the captive breeding programme which is essential for the future of the species."

The Rangatira birds will be matched with suitable partners to have chicks of their own.

The next generation will then add to the diversity of the small island populations around mainland New Zealand such as Waikawa/Portland Island on the East Coast and Motutapu in Hauraki Gulf.