Cook's Petrel

The Cook's petrel, known to the Maori as the tītī or sometimes referred to as the blue-footed petrel, is a diminutive member of the gadfly petrels. This seabird, with its pale grey upperparts adorned by a distinctive dark grey "M" across the wings, and contrasting white underparts, is a graceful denizen of the skies. It measures approximately 25–30 cm in length, boasts a wingspan of 65–66 cm, and tips the scales around 200 grams.

Identification Tips

When observing Cook's petrel, one should note its long, black bill equipped with tubular nostrils, a feature shared by all Procellariiformes. This adaptation grants the bird an exceptional olfactory sense, vital for locating sustenance and nesting sites in the absence of light.

Habitat

Cook's petrel is a breeding endemic to New Zealand, where it makes its home on just three small islands: Little Barrier Island, Great Barrier Island, and Codfish Island. During the breeding season, which spans the southern summer from October to May, it prefers to nest in burrows and rock crevices, often selecting densely forested ridges as its nursery.

Distribution

Outside the breeding season, Cook's petrel embarks on a migratory journey across the Pacific Ocean. It has been spotted as far afield as the west coast of the United States and the tropical western coast of South America.

Behaviour

This highly pelagic species, except when nesting, is known for its long-distance flights over the ocean. Its breeding islands are a hub of activity during the summer months, with a characteristic three-part kek, kek, kek call echoing through the air.

Diet and Feeding

The diet of Cook's petrel primarily consists of fish and squid, supplemented by occasional crustaceans. Its foraging strategy takes full advantage of its pelagic lifestyle, often far from land.

Conservation status

The IUCN has classified Cook's petrel as Vulnerable. With an estimated population of 1,258,000 individuals, the species faces threats from introduced predators such as pigs, dogs, rats, and cats, as well as native weka on Great Barrier Island. These predators are known to raid nests and burrows, preying on eggs and young, leading to a decline in numbers from historical levels.