Grey-faced Petrel

The grey-faced petrel breeds only in the north of North Island, New Zealand. Colonies are largely found on offshore islands, although small remnant populations exist on the mainland at several sites, and birds are successfully breeding in areas with sufficient control of invasive mammalian predators such as rats, cats, and stoats. The largest breeding colony is found on Moutohora Island, with an estimated 95,000 breeding pairs. Outside of the breeding season, individuals range over the subtropical southwest Pacific Ocean, including Australia and Norfolk Island, keeping mainly in the area between 25 and 50 degrees south. Vagrants may occasionally enter Antarctic waters.

Grey-faced petrels have a considerably large population and range, and so are listed as least concern by the IUCN. Furthermore, it is listed as Not Threatened under the New Zealand Threat Classification System due to population increases. One of the largest threats to grey-faced petrels is at breeding grounds, where they are predated on by introduced mammals such as Norway rats. Unattended eggs and young/weak chicks are particularly susceptible to predation, which can impact breeding success rates at colonies. Furthermore, burrowing animals such as rabbits can compete and interfere with grey-faced petrel burrows, which may lead to the birds abandoning them. However, pest eradication projects, such as on Moutohora Island, have allowed some of these colonies to flourish. Town lights have been known to attract some young grey-faced petrels, possibly confusing the artificial light for bioluminescent prey.