A specialist search and recovery team has been deployed to recapture the last remaining survivors of a flock of endangered birds that absconded from a predator-free island in New Zealand during coronavirus lockdown.
There are only 250 shore plover or tūturuatu left in the wild and they are the world’s rarest plover. Conservationists have been painstakingly reintroducing them to the mainland after they were almost wiped out by cats and rats by 1880.
The birds survived for another 100 years in a remote colony on the Chatham Islands, 650km west of New Zealand.
Shore plovers are endemic to New Zealand and renowned for their “attitude and friendliness” – traits which alongside their ground nests make them highly vulnerable to predators.
Mana Island off the coast of the North Island’s Kapiti coast was a successful home to an introduced colony of plovers in 2007. But a few short years after being introduced a single rat wiped out half the population, with the rest dying shortly later due to “complications”.
After the 2007 devastation conservationists avoided reintroducing the plover until the pest situation was resolved.
But in April and May they again took the plunge, transporting 29 young birds to the island, some of whom required ministerial approval to travel during the Covid-19 lockdown.
The birds were colour-banded but not tracked, the department of conservation (DoC) said, and it now appears nearly the entire population has again vanished: either having being killed by avian predators such as rūrū, or having flown off to the mainland.
Shore plover recovery group leader Dave Houston from DoC said the birds’ mysterious disappearance was “frustrating”, as substantial time and money had gone into their recovery.
Houston said his team were unsure what exactly had happened to 26 of the birds, though it had tracked three survivors to Plimmerton beach on the mainland, with a search and recovery team hoping to recapture them later this week. Reports from the public have been helping DoC keep tabs on the survivors.
“The birds haven’t stayed at home like we hoped they would,” Houston said.
“We honestly don’t know what is making them leave; but it could be that a single bird decided to fly to the mainland and everyone else followed them – it could be random behaviour, we’re not sure.”
In past releases shore plovers had been found to fly as far south as Christchurch in the South Island, and despite their small size they showed considerable pluck, Houston said.
“It is frustrating, we can give them strict instructions, but they choose not to obey. They are a challenging species to manage, so it’s a great loss to then lose them. But we persist.”
If the three survivors are captured they will be returned to Mana Island and held in an aviary for a month rather the usual week to help them establish “fidelity” to the island, Houston said.
Radio transmitters would also be attached to the birds so conservationists “can determine their fate … We might not find them at all though,” Houston mused. “They’re not very long-range transmitters.”