Poor or non-existent pest control has caused a catastrophe for one of New Zealand's beloved native bird species, conservationists say.
Dr Luis Ortiz-Catedral of Massey University said a lack of pest control in Northland was largely to blame for the disappearance of kakariki, the native red-crowned parakeet.
Last week, Forest and Bird released drone footage of decimated native Northland forests, also blaming inadequate pest control for the destruction of many native trees.
Forest and Bird said possums and other pests were running rampant in northern forests. This week, Dr Ortiz-Catedral said rats, possums, and other pests were killing off kakariki.
"This is a rapid collapse," he said.
Dr Ortiz-Catedral, a conservation biology lecturer and parakeet expert, said the kakariki had almost certainly become extinct in all areas north of Kawakawa.
"As recently as 25 years ago there were anecdotal records of kakariki scattered across Northland from Cape Reinga down to forest patches near Paparoa.
"This means in one human generation they have gone. Your grandparents might have seen these birds, but your parents did not."
Rats and possums were making dens in the same places kakariki liked to nest, Dr Ortiz-Catedral said.
The pests were making themselves at home in trees including puriri, taraire and kahikatea.
"Many people confuse kakariki for the rosellas from Australia that are now common in the north. But rosellas are multi-coloured with mostly red heads, while kakariki are almost totally bright green, which is why the Maori word for green and kakariki are the same."
Forest and Bird Northland conservation advocate Dean Baigent-Mercer said without pest control, many native trees and birds were being wiped out.
"This is happening all over the country which is why we need a Government commitment for five million hectares to come under total and sustained pest control nationally and [a] ten year recovery plan for Northland's forests," Mr Baigent-Mercer said.
"Flocks of kakariki used to be so common their feathers were used as down to stuff mattresses by early European settlers. Now you need to go to the pest free Poor Knights, Three Kings or Hen and Chicken Islands to see kakariki."
Green Party MP Kevin Hague blamed the Government for a nationwide conservation crisis.
He said only 2000 hectares of native, Department of Conservation-managed Northland forest, less than two per cent of all such forest, was receiving adequate pest control.
"We're losing kaka and kakariki in the Far North due to National's conservation cuts. But it's also a story that is happening all over the country," Mr Hague said in a statement.
"Maggie Barry, Minister of Conservation, was unable to answer my straight forward questions in the House on Tuesday about funding levels for multi-pest control operations in Northland."
Ms Barry told the House of Representatives about 60 per cent of these DcC forests were under some form of sustained pest control.
"We spend $3.19 million on multi-pest control in Northland, and if you add what we use in weed control, which is a big problem because it smothers all of the native seedlings, the total is $5.87 million each and every year," the Minister added.