General
Mottled Petrel: Medium-sized petrel; mostly gray with mottled white markings. Face is gray and white; throat, upper breast, anterior superciliary area, lower ear coverts and undertail are white; tail is short. Wings have distinct black bars on white undersides; pale fringes give the upperparts a scaly look. Bill is short and black; iris dark brown; legs and base of feet light, fleshy-pink; rest of feet are black. Sexes are similar. Juvenile is similar to adult but has more noticeable pale scaling above.
Range and Habitat
Mottled Petrel: This species breeds on islands off New Zealand. It is migratory, and visits the Bering Sea and other areas of the northeastern Pacific in spring and summer. They visit the waters off Alaska and British Columbia, and rarely travel south to Oregon and California. This species is pelagic, only coming ashore to breed.
Breeding and Nesting
Mottled Petrel: These petrels are summer breeders, returning in late October to clean out the nests and mate, and laying eggs in December. They are monogamous, mating for life, and reuse the same burrow from year to year. One white egg is laid on a pile of grass in a burrow or crevice. Incubation is carried out by both parents for 54 days.
Foraging and Feeding
Mottled Petrel: These petrels feed mainly on squid, fish and some crustaceans. Usually they feed by dipping their bill and face into the sea whilst still in flight, but occasionally they land on the sea to peck at small prey either on or just under the surface. They sometimes feed in association with the Sooty Shearwater. They do not follow ships.
Vocalization
Mottled Petrel: On breeding grounds gives a repetitive, rapid "ti-ti-ti." Also utters a deep, bugle-note "goo-oo."
Similar Species
Mottled Petrel: Cook's Petrel has white underparts, underwings, and outer tail feathers.