Imperial Shag

Identification

The imperial shag is a striking black-and-white cormorant measuring 70–79 cm in length and weighing 1.8–3.5 kg, with males typically larger than females. Its most distinctive features are its glossy black plumage covering the back and wings, contrasting sharply with a white belly and neck. The species is unmistakable thanks to its vivid blue eye-ring, orange-yellow nasal knob, and pinkish legs and feet. During breeding season, adults display an impressive erectile black crest that is absent in non-breeding plumage. The bill is notably serrated, an adaptation for gripping slippery prey. Subspecific variation exists primarily in cheek and ear-covert coloration: most taxa display white cheeks, while others show entirely black cheeks. Chicks appear uniformly brownish, while immatures are brownish and white with duller facial features and lack the vibrant eye-ring and nasal knob of adults.

Range & Habitat

The imperial shag is native to southern South America, subantarctic islands, and the Antarctic Peninsula. Its range extends from south-central Chile and Argentina southward to Cape Horn, with eight recognized subspecies distributed across the Falkland Islands, South Georgia, the South Sandwich Islands, South Orkney Islands, the Crozet Islands, Prince Edward and Marion Islands, the Antarctic Peninsula and South Shetland Islands, Kerguelen Islands, Heard Island, and Macquarie Island. The species primarily inhabits rocky coastal regions, though it also occurs locally at large inland lakes. Recent molecular studies suggest that despite the wide geographic separation of breeding colonies and the species' sedentary behaviour, genetic evidence points to a circumpolar dispersal from South America following the Last Glacial Maximum.

Behaviour & Diet

The imperial shag is colonial and monogamous, with breeding colonies ranging from small groups to hundreds of pairs. These colonies are often shared with other seabirds including rock shags, southern rockhopper penguins, and black-browed albatrosses. Nests are constructed from seaweed and grass cemented together with mud and excrement, typically containing two to five eggs that hatch after about five weeks. Both parents brood the eggs and chicks, though predation by skuas and sheathbills causes significant losses.

The diet consists primarily of small benthic fish—especially Argentine anchoita—supplemented with crustaceans, polychaetes, gastropods, and octopuses. These skilled divers typically descend to almost 25 m, with recorded dives reaching depths of 60 m to forage on the sea floor. Most feeding occurs in inshore regions, though some populations travel considerable distances from shore.

Best Time & Places to See It

The imperial shag is most readily observed during the breeding season when birds are concentrated in their colonies. The species is not considered threatened and is relatively common throughout its range, with most subspecies numbering over 10,000 pairs. Dedicated travellers to subantarctic and Antarctic regions—particularly the Falkland Islands, South Georgia, the Antarctic Peninsula, and Kerguelen Islands—have excellent opportunities to encounter this species in its natural habitat.

Photography Tips

The imperial shag's bold plumage and distinctive facial features make it a rewarding photographic subject. The striking contrast between glossy black and white plumage is best captured in clear, bright light. During breeding season, focus on capturing the erected crest and vivid blue eye-ring, which are diagnostic features. Patience in colonial settings will yield opportunities to photograph courting pairs, nest-building behaviour, and brooding adults. The bird's aquatic lifestyle offers action photography possibilities, particularly when diving or returning to shore with catch. The white facial patches and orbital ring provide natural focal points that help draw the viewer's eye in composition.