A dark brown petrel with a pale grey throat and heavy hooked black bill resting under scrub at night — Photo: Hilton Ward · CC0 1.0

NativeNot Threatened

Grey-faced petrel

ōi · Pterodroma gouldi

Rarely seen by day. Ōi come ashore after dark at Challenger Island/Little Kawau, from about March to January. At sea, look for a large, all-dark petrel with a pale grey face and a stout black bill.

Story

Ōi breed only in northern New Zealand, in more than 100 colonies on islands and a few mainland headlands. One colony is on Challenger Island/Little Kawau, just 200 m off Kawau's south coast. Cats and rats are the main threats, and numbers have grown as islands are cleared of predators. Some iwi still harvest the chicks each November and December.

Behaviour

Unusually, ōi breed through the winter, laying a single egg from mid-June to late July. They feed at night, mostly on squid, and some forage thousands of kilometres away, as far as eastern Australia. Over the colony after dark they chase each other at high speed in courtship flights, calling 'whis-her' and 'wik-wik'.