The Ōkārito kiwi and Northern brown kiwi have had their endangered status reduced in an updated assessment of threatened species around the world.

Photo: Supplied: Scimex

The change was made on the International Union for the Conservation of Nature's Red List, a catalogue of endangered species.

The updated list noted intensive predator controls on remote New Zealand islands led to the upgrade in the conservation status of the birds from 'endangered' to 'vulnerable'.

"Both species of kiwi have been facing threats including habitat loss and predation by introduced mammals, such as stoats and feral cats. The Northern brown kiwi is also threatened by predation from ferrets and dogs.

"Government and community conservation efforts have focused on predator control, and removing and incubating eggs for release into the wild. The Ōkārito kiwi has increased from 160 individuals in 1995 to between 400 and 450 adults today.

"Overall, Northern brown kiwi populations are estimated to be growing by over two percent per annum, although unmanaged populations continue to decline."

However, the organisation said a wider assessment of New Zealand birds showed many endemic species were in decline, threatened by invasive species.

The report said three species of reptiles found only on Christmas Island - an Australian territory - had gone extinct, and the status of Australia's western ringtail possum was upgraded from 'vulnerable' to 'critically endangered'.

It also said wild rice, wheat and yams were threatened by intensive agricultural production and poor fishing practices caused steep declines in populations of Irrawaddy dolphin and finless porpoises.