In 1972 wildlife officers could find only 18 black robins living on Little Mangere Island. In 1976 there were only seven birds left. These were all moved to Mangere Island where 120,000 trees had been planted to provide better shelter. By 1980 a further two birds had died, and none had bred.
There were only five black robins in the world in 1980, with just a single breeding pair left. The survival of the species hinged on that last pair. The outlook was bleak, but a dedicated team of New Zealand Wildlife Service staff took the daring step of cross-fostering eggs and young to another species to boost productivity.