| Cook's Petrel | |
|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Procellariiformes |
| Family: | Procellariidae |
| Genus: | Pterodroma |
| Species: | P. cookii |
| Binomial name | |
| Pterodroma cookii (G.R. Gray, 1843) |
|
Cook's Petrel (Pterodroma cookii), one of the smallest petrels, is a species of seabird and a member of the gadfly petrels. The bird is 25-30 cm in size, with a 65-66 cm wingspan. It is a member of the subgroup of petrels known as 'Cookilaria' petrels, which includes the very similar Stejneger's Petrel.
This species is highly pelagic, except when nesting, which it does on offshore islands, forest ridges, or steep slopes. The Cook’s Petrel breeds only in New Zealand on three small islands: Little Barrier Island, Great Barrier Island, and Codfish Islands. It migrates to the Pacific Ocean from New Zealand when it is not breeding. It sometimes can be seen well off the west coast of the United States and well off the west coast of tropical South America. Cook's Petrel feeds mostly on fish and squid, with some crustaceans taken.
Among Cook’s Petrel's features, the bill is long and black with tubular nostrils on both sides. As in all members of the order Procellariiformes, this nostril configuration enables an exceptionally acute sense of smell, which the birds use to locate food and nest sites in the dark.
Cook's Petrels use burrows and rock crevices in which to nest, preferring sites on thickly forested ridges. The species was formerly more numerous; the current population estimate is 1,258,000 and declining. It is classified as vulnerable because it breeds on just three small islands. While Little Barrier Island's population remains stable, the other two populations are decreasing. One of these islands has introduced rats and Wekas (a ground-dwelling member of the Rallidae), both of which prey on eggs and nestlings of Cook's Petrel, reducing the population from 20,000 to 100. On Great Barrier Island, introduced pigs, dogs, rats, and cats have attacked nests and burrows, decreasing the population there.
[1] Rayner, Matthew. 7 July 2007 "Cook’s Petrel - Pterodroma Cookii." ARKive - Discover the World's Most Endangered Species. Web. <http://www.arkive.org/cooks-petrel/pterodroma-cookii/#text=FactsStatus>.