It has been just months since they were released on to the 300ha site as juveniles, under an agreement between the Department of Conservation and two runanga: Makaawhio, of South Westland, the guardian of Haast tokoeka, and Kati Huirapa Runaka ki Puketeraki, of Karitane, which is fulfilling the guardian role on behalf of Te Runanga o Makaawhio.
They are the first kiwi to roam Dunedin forest in 140 years.
Orokonui Ecosanctuary Trust chairman Neville Peat said that there were now clear signs the kiwi were becoming territorial, which meant they were getting ready to breed.
He said the birds had been putting on "impressive" amounts of weight since their arrival.
They were frequently seen out and about during the Orokonui After Dark tours.
"They are clearly doing better here than they would be in their natural habitat in the South Westland ranges.
"They're certainly making themselves at home," Mr Peat said.
Incubation of kiwi eggs takes about 80 days, and he believed there could be kiwi chicks roaming about the ecosanctuary as early as the end of this year.
There were no plans to release more kiwi at this stage, because it was not yet known how big the their territories were, Mr Peat said.
"We're not sure how many kiwi could be put on the 300ha site without it becoming overcrowded."
