At a Glance

Formerly a rare visitor to waters off northeastern North America, the Manx Shearwater has increased in recent decades, and has been found nesting on this side of the Atlantic. Many small black-and-white shearwaters in other oceans are closely related, and are sometimes classified as belonging to this same species.
Category
Gull-like Birds, Shearwaters and Petrels
Conservation
Low Concern
Habitat
Open Ocean
Region
California, Eastern Canada, Florida, Mid Atlantic, New England, Southeast
Behavior
Flap/Glide, Rapid Wingbeats
Population
740.000

Range & Identification

Migration & Range Maps

Present in numbers off northeastern North America from May to October. Movements of these birds not well known. Large numbers move north past Bermuda in spring, peaking in March. A few have been recorded off the southeastern United States in winter. Birds from European colonies winter mainly off east coast of South America.

Description

12 1/2-15" (32-38 cm). Sharply contrasting, blackish above, white below and on wing linings. Face is dark; white from throat notches up behind the dark ear patch. Flies with fast wingbeats, short glides.
Size
About the size of a Crow, About the size of a Robin
Color
Black, White
Wing Shape
Pointed, Tapered
Tail Shape
Pointed, Rounded, Short, Wedge-shaped

Songs and Calls

Cooing and clucking notes heard at night in breeding colonies.
Call Pattern
Flat, Undulating
Call Type
Odd, Raucous, Scream

Habitat

Open ocean. Off North America, generally occurs over cooler waters (but it inhabits warm waters elsewhere, including waters off eastern South America). Often feeds closer to shore than other shearwaters. Nests on islands, mostly small islands near mainland.

Behavior

Eggs

One per season. White. Incubation is by both sexes, 47-55 days, rarely up to 63 days.

Young

Both parents feed young. Parents abandon young after about 60 days, and it leaves nest 8-9 days later, going to sea alone.

Feeding Behavior

Forages by plunging into water from low flight, by making shallow dives from surface, or by seizing items at or just below surface while swimming. Swims underwater better than some other shearwaters.

Diet

Mostly small fish. Feeds on a variety of common small fish, especially herrings, sprats, sardines, sand lance; also squid, crustaceans.

Nesting

Breeding behavior known mostly from studies around Great Britain. Usually first breeds at age 5-6 years, and may mate for life. Nests in dense colonies on islands. Activity at colony entirely at night. Courtship not well known, but members of pair spend much time in nest several weeks before egg is laid. Nest: Site is in burrow, usually 3-6 feet long, excavated by both sexes; same burrow may be re-used for several years. Nest chamber is usually lined with small amount of grass, leaves.

Climate Vulnerability

Conservation Status

Apparently increasing off east coast of North America; first found nesting in Massachusetts in 1973, Newfoundland in 1976.

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