Southern fulmar

Taxonomy

The southern fulmar was formally described and illustrated in 1840 by the Scottish zoologist Andrew Smith in Illustrations of the Zoology of South Africa, under the binomial name Procellaria glacialoides. It is now placed with the northern fulmar in the genus Fulmarus, introduced in 1826 by James Stephens.

The genus name derives from Old Norse Fúlmár, meaning "foul-mew" or "foul-gull". The specific epithet glacialoides combines glacialis (from the northern fulmar) with the Ancient Greek -oidēs, meaning "resembling". No subspecies are recognised; molecular data indicate the two fulmar species diverged during the Pleistocene.

Description

This petrel is a large, solidly built bird, 45 cm long with a wingspan of 110 cm. Males average 795 grams, females around 740 grams, though both gain weight at the start of an incubation shift—males reaching 1005 grams and females 932 grams. Its plumage is pale silvery-grey on top and white underneath, with a white head and a light grey crown. The wingtips are blackish, marked by a large white patch and a dark trailing edge.

The legs and feet are a pale blue, while the bill is pink with a black tip and dark bluish naricorns. Young birds have a noticeably thinner bill than adults. In flight, it uses a mix of shallow flaps and long glides, often tilting its head to scan the water. Though generally quiet, it makes loud, cackling calls at the nest or in feeding flocks.

Distribution and habitat

Colonies occur on islands around Antarctica including the South Sandwich Islands, South Orkney Islands, South Shetland Islands, Bouvet Island, and Peter I Island, as well as several sites along the mainland Antarctic coast. At sea in summer it mainly frequents the outer edge of pack ice with water temperatures of -1.5 to 0.5°C. In winter it ranges north to about 40°S, reaching Peru via the Humboldt Current.

Small numbers appear off South Africa, southern Australia, and New Zealand. The species is common, with a population of at least 4 million individuals; about a million pairs breed on the South Sandwich Islands alone. It is classed as least concern by Birdlife International.

Behaviour

Breeding colonies, which may contain hundreds of birds, are on cliffs in ice-free areas, with birds arriving in October. Courtship involves a pair sitting side by side, calling, waving heads, and nibbling and preening each other. The nest is a shallow scrape lined with stone chips, built in a wind-sheltered spot on a ledge, scree slope, or crevice. A single white egg, measuring 76 by 51 mm and weighing about 103 g, is laid in late November or early December.

Incubation lasts about 45 days, with both parents taking turns of 3–9 days. Chicks have white down initially, then grey upperparts and flanks; they fledge after about 52 days. Poor weather can cause high mortality among eggs and chicks; skuas and sheathbills are predators. Breeding success improves from 48% at age 6–8 to 87% at age 18–20.

Southern fulmars often gather in flocks with other seabirds such as Cape petrels where food is concentrated, such as around krill schools, whaling ships, or trawlers. Diet consists mainly of krill and other crustaceans, also small fish like Antarctic silverfish and squid such as Psychroteuthis, Gonatus, and Galiteuthis. Food is usually picked from the water's surface, though the bird occasionally dives.