Fewer than 350 regent honeyeaters are estimated to remain in the wild and the race to save the species has entered a crucial new phase.
Last October, 58 regent honeyeaters were released into the Tomalpin Woodlands near Kurri Kurri, on land owned by Mindaribba Local Aboriginal Land Council.
Mick Roderick, a program manager with BirdLife Australia, said the Tomalpin site was in the top two most important sites for regent honeyeaters, along with the Capertee Valley.
Several wild pairs of the species were present at the time of the release. The wild birds and zoo birds formed mixed flocks, with breeding activity witnessed from September to January.
This was considered an exceptionally long breeding season at a single site, which "does not happen anywhere else that regent honeyeaters occur".
"Eight or nine juveniles fledged. It doesn't sound like much but, when a bird gets down to 300, it's pretty good," he said.
"Wild birds are still present and have been there for over seven months. They would never be anywhere for more than three months at a stretch."
The birds are expected to stay there longer, with spotted gums about to flower.
He said the woodlands were "a massive patch of unfragmented forest and the birds didn't need to go anywhere else".
"It's almost like they're enjoying where they are and they don't want to move. It's quite amazing to be honest," he said, adding there were fresh hopes for their survival.
"There are so many different types of eucalypts that, at any given time, there will probably be something flowering."
Of the 58 birds released, only two confirmed deaths have been recorded, making it the most successful release of regent honeyeaters.
It was a good sign that the released birds were "breeding, surviving and mixing with wild birds".
Satellite transmitter technology is now being used to track the movements of zoo-bred birds. The success of the program has highlighted the importance of the woodlands being protected from development.
"Much of the Tomalpin Woodlands comprises land zoned for industrial development, as part of the ill-fated Hunter Economic Zone," Mr Roderick said.
"The land is highly constrained by a litany of planning regulations, not least the significance to regent honeyeaters, swift parrots and numerous other threatened flora, fauna and ecological communities. Investment stalled years ago and the last attempt at development approval ended in a case before the Land and Environment Court, finding in favour of a residents group."
An Australian National University analysis, released in February, concluded that regent honeyeaters would go extinct within 20 years without intervention.
"Management strategies at their current intensity have limited efficacy to prevent extinction," it said.
The highest priorities to save the species were protecting nests and releasing zoo-bred birds to bolster the wild population.
"To recover the wild regent honeyeater population, the next five years will be critical for implementing the most effective conservation strategy."
Predator suppression, habitat protection and increased rates of habitat restoration were considered crucial. This is precisely what Mr Roderick's work involves. He said nests get predated by possums, goannas and currawongs and storms can also affect them.
The quest for survival is not an easy path.
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