Magellanic Cormorant

Leucocarbo magellanicus

Also known as Rock Shag, this rather small cormorant is fairly common along rocky coasts where it feeds mainly in inshore waters. Nests colonially on cliffs and other steep surfaces, sometimes on jetties with colonies of Imperial Cormorants. Adult is distinctive with a white body, black head and neck with variable white face patch, and a red eyering. All-dark juvenile told from Neotropic Cormorant by pink feet and dark face with reddish eyering.

Identification

At a distance, the rock shag is a black and white bird, with head, neck and upperparts black and chest and underparts white. Closer up, the black areas vary from metallic blue to oily green, and are flecked with white in places. The legs and feet are a pink, fleshy colour, and the bare flesh around the beak and eyes is brick red. In breeding condition, there is a blackish though not very prominent crest on the forehead, and a distinctive white ear patch. There is even less sexual dimorphism than in most cormorant species, but males are 5%-10% larger on most size measurements.

Taxonomy

The rock shag was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it in the genus Pelecanus and coined the binomial name Pelecanus magellanicus. Gmelin based his description on the "Magellanic shag" that had been described in 1785 by the English ornithologist John Latham in his book A General Synopsis of Birds. Latham had in turn based his description on a specimen in the Leverian Museum and the account made by Georg Forster of his visit to Tierra del Fuego in December 1774 during James Cook's second voyage to the Pacific. The rock shag was formerly placed in the genus Phalacrocorax but based on the results of a molecular genetic study of the cormorants published in 2014, the species was moved to the genus Leucocarbo. The genus had been introduced in 1856 by the French naturalist Charles Lucien Bonaparte. The genus name combines the Ancient Greek leukos meaning "white" with the name Carbo introduced by Bernard Germain de Lacépède in 1799. The species is monotypic: no subspecies are recognised.

Scientific name
Leucocarbo magellanicus
Authority
(Gmelin, JF, 1789)
Order
Suliformes
Family
Phalacrocoracidae
Genus
Leucocarbo

Range and habitat

Breeding range
SA : coastal sc Chile and sc Argentina to Cape Horn and Falkland Is.
Non-breeding range
to coastal s Brazil
Migration
Complete migrants

Behavior

Like all cormorants, the rock shag feeds by diving for underwater prey. It feeds close to shore, often diving at the edge of kelp beds and apparently finding small fish (predominantly cod icefishes, Patagonotothen species) sheltering among the weed. Studies with depth gauges suggest that it is a fairly shallow diver, typically going about 5 m below the surface with few individuals diving deeper than 10 m, although its prey mainly comes from the sea floor. Dive times are typically around 30 seconds. Its breeding range overlaps markedly with that of the imperial shag Leucocarbo atriceps, but the two species' foraging ranges are different since the imperial shag tends to dive in deeper water, further out from shore.<p>The rock shag usually nests on ledges on steep, bare, rocky cliffs. It normally lays three eggs, though nests of from two to five eggs have been seen. Nesting colonies range is size from five pairs to nearly 400.

Conservation

Population trend
unknown

Photos

Distribution

Bird Calls

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