ID Keys: Dark and light phase individuals exist, but both have white
on primaries, black underwing coverts. Large and bulky overall.
The
South Polar Skua is a large, predatory seabird that is found with regularity
of both coasts of North America. They are long-distance migrants, as
their breeding grounds are barren areas of Antarctica. While South
Polar Skuas do foraging for their own prey, they are also known for their
very aggressive actions in stealing food from other bird species. When
a South Polar Skua identifies another bird that has captured a fish, the
Skua will pursue the bird in flight, jostling it or even grabbing it with
its bill and shaking it in an effort to make the other bird drop its prey.
They are equally aggressive as predators on their breeding grounds, where
nearby penguin colonies may be terrorized by South Polar Skuas coming into
raid the colony for penguin eggs or young chicks.
Habitat
During the breeding season, they are
found in barren areas of Antarctica. Outside of the breeding season,
South Polar Skuas are highly pelagic, typically found well offshore.
Diet
Mostly feeds on fish, especially when away
from the breeding grounds. In some breeding areas, South Polar Skuas
feed heavily on eggs and chicks of other breeding birds, including penguin
colonies.
Behavior
Forages by flying over the surface of
the water and plunging into the water when food is spotted. They will
also sometimes float on the ocean's surface and directly grab food items
that come into range. South Polar Skuas will often steal food from
other birds, even grabbing gulls and other seabirds in flight and shaking
them to make them drop their catch.
Nesting
The South Polar Skua builds a simple
scrape nest on the ground, in a mossy area or area of soft soil. The
female usually lays 2 eggs, and both parents help to incubate them.
When the eggs hatch, both parents help to feed them. Young usually
fledge after 7 to 8 weeks.
Song
Away from their nesting grounds, South Polar
Skuas are usually silent.
Migration
Nests in select locations in
Antarctica. Disperses widely across the Atlantic and Pacific oceans
after the breeding season.
