Wellington (AFP)

An epidemic is hitting the world's largest parrot, the endangered kakapo, on Thursday, New Zealand scientists said on Thursday.

One of the last populations of kakapos living on Cod Island, an isolated land in southern New Zealand, has been struck by a fungal respiratory infection called aspergillosis, said the Department of Conservation ( DOC).

Seven parrots died, including two adults, and 36 receive treatment, according to the DOC. This represents a huge loss for a species with fewer than 150 adult specimens.

"Aspergillosis has a devastating impact on the kakapo," DOC said Thursday in a statement.

This new threat comes as a few weeks ago scientists were celebrating an exceptional breeding season for this nocturnal bird unable to fly, which was thought extinct.

Thanks to sustained efforts over several decades, the number of kakapos - about fifty in the 1990s - has increased slightly.

The closely monitored breeding program counted 249 eggs laid, giving hope that 75 chicks would survive this year, twice the previous record.

But efforts are now focused on saving birds infected with Aspergillosis, which appeared to have killed only one kakapo before this year, according to Auckland Zoo veterinarian James Chatterton.

"This is an unprecedented threat and we are trying hard to understand why it happened this year," he told TVNZ.

"Our hypothesis at the moment is the climate: it was a very hot year in the South."

The heat and overpopulation of nests on Cod Island could have resulted in an abundance of aspergillosis spores.

The kakapo, whose name means night parrot in Maori, was once so common that a European explorer had said they could be dropped from trees like apples.

But they disappeared little by little because of the introduction of predators like cats and dogs and because of their restrictive reproductive habits: they mate only every two to four years, when the rimu, a tree native to New Zealand, gives a lot of fruit.

? 2019 AFP