Grey-faced Petrel

The Grey-faced Petrel, Pterodroma gouldi, is a large seabird endemic to New Zealand's North Island. It boasts a body length of 42–45 cm and an average weight of 550 grams. Its plumage is predominantly dark black-brown, akin to the Black-footed Albatross, with a black bill. Notably, it features pale grey to buff feathers at the base of the bill and throat, and its long wings facilitate a buoyant flight style.

Identification Tips

When identifying the Grey-faced Petrel, look for its dark black-brown coloration and the contrasting pale grey or buff feathers at the base of the bill and throat. The bird's black bill and long, buoyant wings are also distinctive features. Be mindful of potential confusion with the Great-winged Petrel, especially where their ranges overlap in the Tasman Sea, as they are morphologically similar.

Habitat

The Grey-faced Petrel primarily nests on offshore islands in the north of New Zealand's North Island, with some remnant mainland populations persisting in predator-controlled areas.

Distribution

This species breeds exclusively in the northern regions of New Zealand's North Island. Outside the breeding season, it roams the subtropical southwest Pacific Ocean, including waters off Australia and Norfolk Island, typically between 25 and 50 degrees south latitude. Occasionally, vagrants may venture into Antarctic waters.

Behaviour

The Grey-faced Petrel exhibits a remarkable breeding cycle, with adults embarking on a pre-laying exodus lasting up to 70 days. Post-breeding, adults migrate to the seas off eastern and southern Australia for their annual feather moult.

Breeding

Breeding begins with the petrels returning to colonies from mid-March, with burrow preparation in April and courtship peaking by mid-May. Egg-laying occurs from mid-June to late July, and both parents share the incubation duties over approximately 55 days. Chicks are then fed for about 120 days before fledging in December or January.

Similar Species

The Grey-faced Petrel can be confused with the Great-winged Petrel, Pterodroma macroptera, due to their morphological similarities.

Diet and Feeding

These petrels primarily hunt at night, targeting squid, fish, and crustaceans. They may also scavenge. Their prey is often bioluminescent, which the petrels may use as a visual cue for hunting.

Conservation status

The Grey-faced Petrel is classified as Least Concern by the IUCN and Not Threatened under the New Zealand Threat Classification System. However, they face threats from introduced mammals at breeding grounds and competition from burrowing animals like rabbits. Conservation efforts, including pest eradication, have been beneficial for some colonies.