"This is a cause for celebration ... that there are still safe places to release kiwi," Rob Fenwick, chairman of the Kiwis for Kiwi Trust, said after a powhiri welcoming the birds.
"But there is also a sense of tragedy ... that this bird, our national symbol, which used to populate our lands in its millions, is now being rescued egg by precious egg and bird by precious bird."
Only 1500 of the Coromandel brown kiwi remain in the wild.
The five introduced to Motutapu today came from Project Kiwi, a volunteer organisation that has been breeding the bird for 16 years.
Those released have been individually microchipped so they can be identified in the future. But none are fitted with devices to track their movements or progress on the island.
Conservationists will rely heavily on anecdotal evidence to judge how the species is managing but it is expected that up to 300 kiwi will one day call Motutapu home.
Previous studies of the breed suggest they will thrive on the island, which joines pest-free Ringatoto where conservationists are also eyeing as a potential future habitat for them.
Kiwis for Kiwi patron Sir Graham Henry, who was meant to speak at today's ceremony and release one of the birds, could not make it due to the funeral of All blacks coach Steve Hansen's father, Des Hansen, in Christchurch.
"Today marks the one-year anniversary of our Rugby World Cup victory and now, as a nation, we embark on a new challenge: one to save our national icon," Henry said in a statement.
"The battle to save our kiwi is far from over and without help we could lose our national icon."
Ruud Kleinpaste, a member of Kiwis for Kiwi, said it was a momentous day in the future of kiwi.
"This is yet another step in the restoration of Aotearoa," he said.
Coromandel brown kiwi
* Population about 1500
* Genetically different to all other brown kiwi
* Introduced to Motutapu to strengthen the species
* 50 to be introduced to Motutapu over the next six years
* Up to 300 expected to call Motutapu home in the future