The discovery of more night parrots in a remote national park in central-west Queensland has increased the known range of the bird by four times, Australian Wildlife Conservancy (AWC) says.

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The find significantly increases the known number of birds and the area inhabited by the elusive parrot - often described as the world's most mysterious bird - which had been thought to be extinct for more than 75 years.

Queensland Environment Minister Steven Miles said a team of researchers had confirmed three active nests with eggs, a pair of parrots and the recorded calls of three more of the endangered birds in Diamantina National Park.

"After more than a century in the shadows the elusive night parrot is once again in the spotlight," Dr Miles said.

"This is exciting news and very timely as Australia celebrates National Bird Week.

"What a great addition to the 2016 census of our native birds."

The night parrot was rediscovered by naturalist John Young in 2013 and he was also on the field team that made these most recent finds as part of a survey being undertaken by the AWC along with the Queensland Parks and Wildlife Service (QPWS).

John Young rediscovered the night parrot three years ago after it was thought to have been extinct for 75 years. ( Supplied: Australian Wildlife Conservancy )

"John Young has done it again," AWC's chief executive Atticus Fleming said.

"It's great news for the night parrot, a significant range expansion and we expect a significant expansion of the population."

Mr Fleming said the AWC and QPWS had effectively put in place "an interim response plan".

"We're mobilising some additional resources to do both the additional science that is needed but also to try and take out some of the key threats such as feral cats," he said.

A restricted access zone has also been declared over the area to ensure the safety of the birds, with fines up to $365,700 or two years' imprisonment for unauthorised access.

Future looking bright for night parrots

Researchers at Pullen Pullen Reserve recently reported they had located more birds on a neighbouring property.

Mr Fleming said: "There's a lot that we don't know but the discovery gives us hope we'll find more populations, both in central western Queensland but potentially even in other states," he said.

The night parrot was rediscovered by naturalist John Young in 2013. ( News Video )

"As we learn more about the night parrot, its future starts to look brighter."

AWC carried out the survey as part of a risk assessment related to a proposed predator-free fenced area in Diamantina National Park.

Concerns had been raised about the impact of the fence on night parrots and the state's only wild bilby population.

That project will now be deferred while the new information is assessed.

"Essentially that risk assessment will be ongoing," Mr Fleming said.

"Diamantina's a very big area and there are a whole lot of other species that need to be protected so we need an integrated plan that can deliver conservation for bilbies, kowari, plains-wanderer and of course the night parrot," he said.