• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Brown Skua - BirdForum Opus

Alternative names: Southern Skua, Subantarctic Skua, Antarctic Skua, Falkland Skua

Adult. Race S. a. lonnbergi
Photo © by Joseph Morlan
Salisbury Plain, South Georgia, 5 March 2018
Stercorarius antarcticus


Race S. a. lonnbergi displaying
Photo © by Rodrigo Tapia
Ardley Peninsula, King George Island, South Shetland Archipelago, Antarctica, January 1992

Size: 52-64 cm (20½-25¼ in), wing 35.5-40.2 cm, wingspan 126-160 cm, females on average are larger in most measurements, most noticeably in wing length.
Nominate subspecies

  • Brown overall plumage, variable from light to dark
  • Pale streaking above
  • Dark cap (often reduced to a mask in light morph birds)


Other races are larger, darker and less streaked above. Juveniles uniformly dark.


Circumpolar Subantarctic islands, Antarctic Peninsula, Tristan da Cunha and Gough Islands; Falkland Islands and southern Argentina from Chubut to Tierra del Fuego.


This species has been placed in the genus Catharacta with the other large skuas (Sibley & Monroe, 1993; Clements, 2000).

Older texts and some current field guides will treat Brown Skua as a part of Great Skua.


Nominate race
Photo © by zweiblumen
East Cove, Falkland Islands, 2004

There are 3 subspecies[1]:

  • S.a. antarcticus breeds in the Falkland Islands, and south-east South America: Smallest, most heavily streaked.
  • S.a. hamiltoni breeds on Tristan da Cunha and Gough Island: Larger, darker, narrower streaks.
  • S.a. lonnbergi breeds on the Antarctic Peninsula and Subantarctic Islands: Like S. a. hamiltoni but larger.

The subspecies lonnbergi has been treated as a full species Stercorarius lonnbergi by some authorities.[2]


Pelagic. Inland (during breeding season)



Juvenile. Race S. a. lonnbergi
Photo © by Joseph Morlan
Salisbury Plain, South Georgia, 5 March 2018

Oct-Nov onwards, on flat grassy areas or short grass heaths. Nest is an unlined or sparsely so, scrape. 1-2 eggs, incubated 28-32 days, young leave nest within 1-2 days and fledge in 40-50 days. Sexual maturity at six years.


Scavenger at refuse tips, predates penguin eggs and chicks and burrow nesting seabirds at night.


  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2017. The eBird/Clements checklist of birds of the world: v2017, with updates to August 2017. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
  2. Avibase
  3. BF member observations
  4. Handbook of the Birds of the World Alive (retrieved May 2018)

Recommended Citation

External Links

GSearch checked for 2020 platform.1