The Chatham petrel is also known by its Maori name, ranguru. Fossil evidence indicates that this species was once widespread throughout the Chatham Islands of New Zealand [New Zealand Department of Conservation (NZDOC) 2001b]. However, the species is currently only known to breed on South East Island (Rangatira) (BirdLife International 2007a) and, as a result of recent release efforts, on Pitt Island (BirdLife International News 2006) within the Chatham Islands. The population of this species is very small, estimated at 800-1,000 birds based on recent research and banding studies (Taylor 2000), and is showing a decreasing population trend (BirdLife International 2007a). It is estimated that fewer than 200 pairs breed per year (NZDOC 2001b). The IUCN considers the Chatham petrel to be ``Critically Endangered''(BirdLife International 2006a). Banding studies have shown that young birds of this species remain at sea for at least two years before returning to land to breed and nest. Based on limited feeding habits data, the species preys on squid and small fish (Heather and Robertson 1997, as cited in BirdLife International 2000).