General

Cook's Petrel: Small petrel with slate-gray back and upperwings marked by a distinctive black M pattern. Underparts and underwings are white. Face is white with small, dark mask. Wings are long and slender. Tail is gray with black-tipped central feathers and white edges. Sexes are similar.

Range and Habitat

Cook's Petrel: Breeds on islands off New Zealand; migrates regularly to Pacific waters near North America. Pelagic; comes to land only to breed.

Breeding and Nesting

Cook's Petrel: One white egg is laid on a high, forested island slope on bare soil or in a burrow dug or cleaned out by both parents. Incubation ranges from 45 to 55 days and is carried out by both parents.

Foraging and Feeding

Cook's Petrel: Eats squid and small fish. Skims water and snatches prey from surface.

Vocalization

Cook's Petrel: On breeding grounds gives a rapidly repeated "ti-ti-ti" or "whik-kek-kek."

Similar Species

Cook's Petrel: Buller's Shearwater is larger, has back head, dark wedge-shaped tail, more contrasting M on back, and lacks dark ear patch.