"We're thrilled Bradshaw and Charlie paired up on Motutapu and have become the first takahe to hatch chicks on the island," said Deidre Vercoe Scott, manager of the Department of Conservation (DOC) Takahe Recovery Group.
"This is a good sign they'll have more chicks in the future. Once takahe pair up, they tend to stay together, if they're breeding successfully."
Takahe produce one to three eggs a year, she said, with both parents taking turns to incubate the eggs and feed the chicks until they're three months old.
Ms Vercoe Scott said the first chicks to be born on the island mark an important step in the effort to ensure their survival.
"There are only 260 takahe in the world. Hatching our first chicks on Motutapu is a huge event in the work to save takahe," she said.
"We've eagerly anticipated the arrival of the first takahe chick on the island, so to have two chicks hatched in one go is very exciting. It marks the start of Motutapu as an important breeding site for takahe."
Ms Vercoe Scott said the other pest free islands which house takahe - Kapiti, Mana, Maud and Tiritiri Matangi - are running out of space, making Motutapu "crucial in enabling the takahe population to grow".
The first takahe were released on Motutapu two years ago, after the island and nearby Rangitoto Island were declared free of stoats and other pests. Since then, 17 adult takahe have been released on Motutapu.
The arrival of the chicks on Motutapu coincides with the 65th anniversary of the re-discovery of takahe. They were thought to be extinct for around 50 years, but were found on November 20, 1948, by Dr Geoffrey Orbell, in the Murchison Mountains deep in the Fiordland National Park.