Grey-faced Petrel

The Grey-faced Petrel, known as Pterodroma gouldi, is a large seabird endemic to New Zealand's North Island. It is a robust bird, with a body length ranging from 42 to 45 centimeters 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 has pale grey to buff feathers at the base of the bill and throat, which contrast with its darker overall coloration.

Identification Tips

When observing the Grey-faced Petrel, look for its long wings that facilitate a buoyant flight style. The bird's dark coloration can be a distinguishing feature, but be aware that it can be easily mistaken for the Great-winged Petrel, especially where their ranges overlap in the Tasman Sea, due to their morphological similarities.

Habitat

This species nests predominantly on offshore islands, with some remnant mainland populations that are successfully breeding with adequate control of invasive mammalian predators.

Distribution

The Grey-faced Petrel breeds exclusively in the northern regions of New Zealand's North Island. The largest known breeding colony is on Moutohora Island. Outside the breeding season, these birds roam the subtropical southwest Pacific Ocean, including waters near Australia and Norfolk Island, generally between 25 and 50 degrees south latitude. They have also been known to venture into Antarctic waters on occasion.

Breeding

Breeding begins with the return to colonies in mid-March, with egg-laying peaking in early July. Incubation takes about 55 days, and chicks are left alone during the day from a very young age. Parents may travel up to 600 km to feed their offspring, which fledge in December or January.

Similar Species

The Grey-faced Petrel is morphologically similar to the Great-winged Petrel, particularly where their ranges overlap.

Diet and Feeding

These petrels primarily hunt squid, fish, and crustaceans, often scavenging for this food. They are nocturnal hunters, utilizing the bioluminescence of their prey as a hunting cue.

Conservation status

The Grey-faced Petrel is classified as Least Concern by the IUCN and Not Threatened under the New Zealand Threat Classification System. Predation by introduced mammals and competition with burrowing animals like rabbits are significant threats at breeding grounds. However, pest eradication efforts have been beneficial. Additionally, young birds are sometimes attracted to town lights, mistaking them for bioluminescent prey.