Manx Shearwater
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.
All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Gull-like Birds, Shearwaters and Petrels
IUCN Status
Least 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.
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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.