Wilson’s Storm-Petrel
Wilson's Storm-Petrel
Oceanites oceanicus
At a Glance
Despite its small size and seemingly weak flight, this bird is at home on the roughest of seas, flying in the troughs of the waves during gales. It also travels huge distances -- from the Antarctic to the edge of the Arctic. Although it nests only in far southern oceans, Wilson's Storm-Petrel is often the most common seabird off the Atlantic Coast of the United States.
All bird guide text and rangemaps adapted from by Kenn Kaufman漏 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Gull-like Birds, Storm-Petrels
IUCN Status
Least Concern
Habitat
Open Ocean
Region
California, Eastern Canada, Florida, Mid Atlantic, New England, Southeast
Behavior
Direct Flight, Flap/Glide
Population
14.000.000
Range & Identification
Migration & Range Maps
Moves north in March to May, most commonly in Atlantic and Indian oceans, many crossing Equator. Common off eastern North America during northern summer. Fair numbers have been found recently far off the California coast, but status in North Pacific is still poorly known.
Description
7" (18 cm). Black, with obvious white rump patch, short squared-off tail. Flies with quick, shallow wingbeats, like a Purple Martin. May patter feet on water while hovering; feet may extend past tail tip in level flight. Yellow webs between toes (hard to see).
Size
About the size of a Robin, About the size of a Sparrow
Color
Black, White
Wing Shape
Pointed, Tapered
Tail Shape
Notched, Rounded, Short, Square-tipped
Songs and Calls
A soft peeping, heard at close range when birds are feeding.
Call Pattern
Flat
Call Type
Raucous
Habitat
Open ocean. Widespread at sea, from tropical and subtropical waters to edges of pack ice. Off North America mainly over continental shelf, may concentrate over upwellings and where warm and cool water currents meet, as along edges of Gulf Stream. Seldom close to land in nonbreeding season.
Sign up for 探花精选's newsletter to learn more about birds like the Wilson's Storm-Petrel
Behavior
Eggs
One. White, usually with reddish-brown dots at larger end. Incubation is by both sexes, usually 40-50 days, sometimes 38-59.
Young
Fed by both parents. Period from hatching to departure from nest (46-97 days) varies considerably, probably depends on rate of feeding. Young is independent of parents after leaving nest and going to sea.
Feeding Behavior
Takes food from surface of water. Forages mostly by hovering with feet touching water and picking at surface with bill, also by dropping into water and then resuming flight, sometimes by picking at items while swimming.
Diet
Small crustaceans, fish. Feeds mainly on crustaceans (especially euphausiid shrimp and amphipods) and small fish, also small squid, marine worms, other small organisms. Scavenges at natural oil slicks and carrion, and will follow ships to pick at offal.
Nesting
Breeds on islands and cliffs of Antarctic region and around southern South America. Nesting is generally November to May. Males may arrive at nesting sites first, and unmated males may sit near nest entrance and call to defend site and attract female. Nest: Site is in crevice or hole in cliff, among rock piles, or in burrow. Nest chamber usually lined with feathers and moss, sometimes bare.
Climate Vulnerability
Conservation Status
Total population certainly runs to many millions. Despite its abundance, this species (like many other seabirds) would be vulnerable to pollution, overfishing, or other degradation of the Antarctic Ocean.