''It is known that young kiwi are particularly vulnerable to predation by stoats until they reach 1200g in weight, usually somewhere between 6 and 18 months old,'' island ranger Emma Craig said.
"A creche site like predator free Matakohe-Limestone Island takes stoats out of the equation until young kiwi are large enough to fight them off. They come to the island as 1-2 week old fluff-balls, and leave as big stroppy kiwi really to settle down, find a mate, and start making chicks of their own."
At only 38 hectares, Matakohe-Limestone Island punches above its weight for pumping out kiwi, Ms Craig said.
She estimates there are about 70 more on the island to be transferred in the coming years.
The event to send off the kiwi to their new homes was overseen by Te Parawhau kaumatua Fred Tito and attended by about 60 invited guests including Green Party MP Marama Davidson, Whangarei Mayor Sheryl Mai, and Whangarei District councillor Anna Murphy.
Like all the kiwi raised on Matakohe-Limestone Island, the four released on Sunday went to new homes in areas that have extensive trapping and/or toxin operations in place to control stoats, and excellent community support to ensure dogs are kept under control and away from kiwi at all times.
Many of these release sites have been along the Kiwi Coast, with Sunday's four heading to Parua Bay.
About 400 people turned up to the Backyard Kiwi event to welcome the kiwi to their community, and on Monday the kiwi were reported to be doing well and keeping dry despite Cyclone Hola.
The kiwi have been named. Rukuwai and Ross were named by their new community at Parua Bay, and Harikoa and Mokopuna were named as they left Matakohe-Limestone Island.