Cook’s Petrel, Pterodroma cookii
Cook’s Petrel, (Pterodroma cookii), is a species of seabird and a member of the gadfly petrels. The breeding habitat of this species is limited to three small islands in New Zealand: Little Barrier Island, Great Barrier Island, and Codfish Island. It migrates to the Pacific Ocean when it is not breeding. It can sometimes be seen well off the west coast of the United States and tropical South America.
The adult is 9.8 to 11.8 inches in length with a 26-inch wingspan. The bill is long and black with tubular nostrils on both sides. As in all members of the order Procellariiformes, the nostril configuration enables an exceptionally acute sense of smell, which the bird uses to locate food and nesting sites in the dark.
Cook’s Petrel feeds mainly on fish and squid, but will also take in some crustaceans. It uses burrows and rock crevices for nesting, preferring sites on thickly forested ridges.
The numbers of this species, currently at about 1.3 million, are steadily declining. It is considered vulnerable because it breeds on just three small islands. Whole the population on Little Barrier Island remains stable, the other two populations are decreasing. Introduction of rats and Wekas (small ground-dwelling birds) have caused numbers of this species to drop from 200,000 to only 100 on Codfish Island. On Great Barrier Island, introduced pigs, dogs, rats, and cats have affected populations there.