The birds, which have been released onto private properties in the Western Riverina near Hay, were hatched at Taronga Western Plains Zoo, Taronga Zoo and Werribee Open Range Zoo.

It's part of a plan to boost the plains-wanderer population. The birds are considered endangered.

The private lands where the birds were released are part of the Paddocks for Plains-wanderers' program, where landholders receive support to manage their ground cover for livestock production and plains-wanderer conservation.

So far, the program has protected 13,000-plus hectares of plains-wanderer habitat across NSW's Riverina Plains.

Taronga Conservation Society Australia chief executive Cameron Kerr said the plains-wanderers were a unique Australian bird whose genetic history dated back millions of years, which was why breeding the birds, and releasing them back into the wild was so important.

"This first NSW release is a huge milestone in our conservation efforts for this species, and it is so rewarding seeing these little birds returned to their wild habitat, where we hope they will thrive," he said.

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NSW Environment Minister James Griffin said it was a monumental step towards reversing the plight of the small, ground-dwelling species.

"It's thought there are now fewer than 1000 of these birds in the wild due to threats including grassland habitat loss, severe drought and fox attacks," Mr Griffin said.

"But now, we're working in partnership with private landholders to restore their habitat and protect it so plains-wanderers can thrive."

There are another 37 plains-wanders in the conservation breeding program at Dubbo's Taronga Western Plains Zoo and eight at Taronga Zoo in Sydney.