With incubation normally taking around 75 days, the estimated hatch date of November 17 came and went last week without a peep from the kiwi.
On Saturday the egg was candled again and it was concluded that the embryo had probably died.
"We had been hoping like anything, but were beginning to think that it had died," Ngā Manu manager Matu Booth said.
"But we decided to err on the side of caution and leave it a few more days."
On Saturday evening, Ātaahua unexpectedly laid a fourth egg of the season.
The appearance of the fourth egg helped temper the disappointment of the previous egg's failure, but it created another tough decision for staff.
Remove the "failed" egg to safeguard the new egg from being damaged or leave it.
"We decided to leave them both in the nest for the time being and monitored the eggs daily."
On Wednesday morning, the nest was checked as usual and when Ngā Manu's Dave Banks saw the eggs, his heart sank.
"At first glance Dave's heart sank when he thought the new egg had been broken.
"But then he realised that the broken shell belonged to the egg which was starting to hatch."
After 83 days incubating, the egg was beginning to hatch.
Normally taking a few days to emerge, staff helped the chick along because they were concerned the egg membrane had started to dry out and the chick might become trapped in the shell.
After receiving advice from Pūkaha staff, it was decided to gently remove the shell from around the kiwi.
"It only took a couple of gentle twists for the kiwi to slide from the egg and into full view.
"It normally takes a few days to hatch, but this was quite a fast hatch process, especially with the intervention, we had our hearts in our mouths."
But staff knew they had got it right when the chick slid out as soon the shell was popped.
"As soon as it slid out we knew we got that part of it right. There was huge elation from staff."
And just like that Ngā Manu has another kiwi chick.
Going through the incubation and hatching process at Ngā Manu is part of the plan to help Ātaahua and Puha become a breeding couple capable of breeding in the wild.
"We were encouraged to take away the first egg, because that's the first egg that Ātaahua and Puha have produced that is fertile.
"So it went away to Pūkaha and is now back in an enclosure adjacent to its parents and doing very well.
"Because the adult birds will be released into the wild, we wanted them to experience the whole process, so the second time we left the egg with them to incubate."
The chick will be put in a separate enclosure to its parents in a few days' time to be monitored in a temperature controlled environment.
"Pulling the chick out of the egg, it was a real buzz we didn't quite know what to expect.
"This morning was another milestone as it made it through the night, drying out and now all fluffed up, looking more like a little kiwi."
With the first chick already on display at the kiwi night encounters, the second chick will be on display once it is big enough to be moved into the same enclosure.
With the first chick being announced as a female after sending a feather away for DNA testing, it will be a while until the gender and name of the second chick will be announced.
Fingers are now crossed that the fourth egg of the breeding season will produce a third kiwi chick for Ngā Manu.
