Rangatira is most famous for being the habitat for the endangered black robin, rescued from near extinction by a dedicated team led by Don Merton, who used foster parent birds to raise the chicks of black robin. The island has been identified as an Important Bird Area by BirdLife International because it supports large breeding colonies of broad-billed prions (330,000 pairs), Chatham petrels (up to 1000 pairs) and white-faced storm petrels (840,000 pairs). Rangatira was the stronghold and last remaining breeding site for the Chatham petrel until recently; new colonies on Pitt and Chatham Islands are being established.