Species: Stercorarius maccormicki

South Polar Skua

Species

Birds

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Salish Sea-reliant birds

Encyclopedia of Puget Sound

See Balch (1981) for detailed information on skua identification.

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Aves

Order

Charadriiformes

Family

Stercorariidae

Genus

Stercorarius

NatureServe

Source:
ELEMENT_GLOBAL.2.101169

Classification

Other Global Common Names

Labbe de McCormick - Mindrião-do-Sul, Gaivota-Rapineira - Págalo Sureño, Escúa Polar, Salteador Polar

Informal Taxonomy

Animals, Vertebrates - Birds - Other Birds

Formal Taxonomy

Animalia - Craniata - Aves - Charadriiformes - Stercorariidae - Stercorarius - breed sympatrically with no hybridization in South Shetlands (AOU 1983); mixed species pairs infrequent at Palmer Station, Antarctica.

Ecology and Life History

See Balch (1981) for detailed information on skua identification.

Short General Description

A medium-sized seabird (skua).

Migration

false - false - true - Most numerous in northern spring and fall off west coast of North America, in northern spring off east coast (National Geographic Society 1983).

Non-migrant

false

Locally Migrant

false

Food Comments

Pursues seabirds and catches food they relinquish; attends fishing boats for scraps. On nesting grounds, diet mainly fishes, also seabirds, small mammals, krill, penguin eggs and young (especially if C. SKUA is absent), and carrion (Terres 1980, Pietz 1987).

Reproduction Comments

Probably both sexes incubate 1-3, usually 2, eggs for 26-29 days (Terres 1980). Eggs hatch late December-early February, though the period is more restricted in a given year. At Cape Crozier, median age of first breeding was 7-9 years; after age 9 years, 91-100% of birds attempted breeding (Ainley et al. 1990).

Ecology Comments

Usually alone on open sea; sometimes in small loose groups in harbors (Stiles and Skutch 1989). At Cape Crozier, nesting success was exceedingly low and variable due to intense storms late in the nesting season; survivorship of individuals aged 2+ years was over 90% (Ainley et al. 1990).

Length

Weight

1156

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1997-12-19

Global Status Last Changed

1997-12-19

Other Status

LC - Least concern

Distribution

Conservation Status Map

Global Range

FG - 20,000-2,500,000 square km (about 8000-1,000,000 square miles) - FG - BREEDING: South Shetland Islands; along the coast of Antarctica (AOU 1983). Largest breeding population is at Cape Crozier, Ross Island, Antarctica (Ainley et al. 1990). NON-BREEDING: at sea regularly to North Pacific, in northern spring, summer, and fall, from Gulf of Alaska south to California, Hawaii, off Japan; to North Atlantic (off Massachusetts, New York, North Carolina, Greenland) (AOU 1983).

Global Range Code

Global Range Description

20,000-2,500,000 square km (about 8000-1,000,000 square miles)

ELEMENT_GLOBAL.2.101169