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(Redirected from Imperial Shag)
Includes King Cormorant; Alternative Names: Blue-eyed Shag; Imperial Shag
Length: 68â€“76 cm (26¾-30 in)
Two main variations: dark-cheeked forms dominate on the Atlantic side while white-cheeked forms dominate on the Pacific side of South America. These forms meet and hybridize (to some extent) in the Patagonia/Magellan Strait region.
Sometimes placed in the genus Leucocarbo.
 Status of questionable forms
Dark-cheeked birds from southern South America have in the past been known as the full species King Shag (Phalacrocorax albiventer) together with birds from the Falklands. Due to reports on hybridization with atriceps these were first lumped as a subspecies under Imperial Shag, and later, the mainland birds were considered a color morph of atriceps leaving the population on Falklands as the current subspecies albiventer. Not everybody agree that the current treatment of the dark-cheeked form is the best possible treatment, but more data are necessary.
Rocky sea coasts.
Male advertisement display consists of a head throwback with the bill open and an aark call while the tail is raised. Mated birds communicate by gaping, head lowering, and throat clicking.
Breeds in small colonies on coastal areas and low islands. Nesting materials include marine algae, feathers, sticks and shells and cemented guano. Clutch size usually 3 chalky-blue eggs but last egg often discarded.
Primarily fish such as Argentine anchoita, but they also eat crustaceans, cephalopods and polychaetes. They are bottom feeders and dive to a depth of almost 25 meters.
Usually resident but disperses from breeding colonies depending on food availability.
Males and females have different calls. During breeding, male gives barking â€śaarkâ€ť and various other honking calls while females have a hissing call.
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