Andy Rouse / Lonnberg's / Subantarctic Skua (Stercoraius antarcticus lonnbergi) displaying aggressive behaviour, South Shetland Islands, Antarctica. (Non-ex)

Hanne & Jens Eriksen / Antarctic skua aggressive display. South Georgia {Stercorarius antarcticus}

Jessie Lane / Antarctic skua {Stercorarius antarcticus} South Georgia (Godthul harbour in background)

Brent Stephenson / Brown Skua (Stercorarius / Catharacta antarcticus) landing on a rock, against a blue sky. Neko Harbour, Antarctic Peninsula, Antarctica, January.

Brent Stephenson / Brown Skua (Stercorarius / Catharacta antarcticus) coming in to land. Mikkelsen Harbour, Antarctic Peninsula, Antarctica, December.

Tui De Roy / South Polar Skua (Stercorarius maccormicki) with Emperor Penguin (Aptenodytes forsteri) chick carcass, Prydz Bay, eastern Antarctica

Tui De Roy / South Polar Skua (Stercorarius maccormicki) pair fighting over Emperor Penguin (Aptenodytes forsteri) chick carcass, Prydz Bay, eastern Antarctica

Chadden Hunter / Antarctic skuas fighting (Stercorarius antarcticus) South Georgia, South Atlantic Islands. Taken on location for BBC Frozen Planet series, 2008

Kathryn Jeffs / Discarded limpet shells at the feeding station of Antarctic skua (Stercorarius antarcticus) Antarctica, February, Taken on location for BBC Frozen Planet series

Eric Baccega / Lonnberg's skua chick (Stercorarius antarcticus lonnbergi) Kerguelen Archipelago, Sub-antarctic, Territory of the French Southern and Antarctic Lands, December

Nick Garbutt / South Polar Skua (Stercorarius maccormicki). Peterman Island, Antarctic Peninsula, Antarctica. February.

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) feeding on Gentoo penguin egg, Antarctica, January

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) feeding on Gentoo penguin egg, Antarctica, January

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) feeding on Gentoo penguin egg, Antarctica, January

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) feeding on Gentoo penguin egg, Antarctica, January

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) portrait, Antarctica, January

Pete Oxford / Antarctic Skua (Stercorarius antarcticus) in flight, West Falkland. Falkland Islands

Sue Flood / Lonnberg's skua (Cataracta lonnbergi) amongst daisies, Enderby Island, New Zealand, sub Antarctic Islands, December

Gabriel Rojo / South polar skua (Catharacta / Stercorarius maccormicki) feeding on dead Adelie Penguin (Pygoscelis adeliae) Paulet Island, Antarctic Peninsula, Antarctica, February

Gabriel Rojo / South polar skua (Catharacta / Stercorarius maccormicki) feeding on dead Adelie Penguin (Pygoscelis adeliae) Paulet Island, Antarctic Peninsula, Antarctica, February

Gabriel Rojo / South polar skua (Stercorarius maccormicki) sitting, Deception Island, Antarctic Peninsula, Antarctica, February

Pete Oxford / Antarctic Skua (Stercorarius antarcticus) portrait, Pebble Island, Falkland Islands

Pete Oxford / Antarctic skua (Stercorarius antarcticus) calling, Pebble Island, Falkland Islands

Pete Oxford / Antarctic Skua (Stercorarius antarcticus) with Rockhopper penguin egg, Pebble Island, off north coast of West Falkland, Falkland Islands

Pete Oxford / Antarctic Skua (Stercorarius antarcticus) with Rockhopper penguin egg, Pebble Island, off north coast of West Falkland, Falkland Islands

Pete Oxford / Antarctic Skua (Stercorarius antarcticus) feeding on dead Rockhopper Penguin (Eudyptes chrysocome chrysocome) Pebble Island, Off north coast of West Falkland, Falkland Islands

Pete Oxford / Antarctic Skua (Stercorarius antarcticus) with Rockhopper penguin egg, Pebble Island, off north coast of West Falkland, Falkland Islands

Steven Kazlowski / Antarctic skua (Catharacta Antarctica) chick on mosses. Western Antarctic Peninsula, Southern Ocean

Steven Kazlowski / Antarctic skua (Catharacta Antarctica) eggs in nest, western Antarctic Peninsula, Southern Ocean

Steven Kazlowski / Antarctic skua (Catharacta Antarctica) chick huddled amongst rocks on the western Antarctic Peninsula, Southern Ocean

Carol Walker / Antarctic skua (Stercorarius antarcticus) attacking Adelie penguin (Pygoscelis adeliae) colony. Paulet Island, Antarctica.

Carol Walker / Antarctic skua (Stercorarius antarcticus) attacking Adelie penguin (Pygoscelis adeliae) colony. Paulet Island, Antarctica.

TJ Rich / South Polar Skua (Stercorarius maccormicki) Antarctic Peninsula

TJ Rich / Antarctic / South Polar Skua (Catharacta / Stercoraius antarcticus) Antarctica

TJ Rich / Antarctic / Falkland skua on nest (Stercorarius antarcticus) Falkland Islands

Pete Oxford / Antarctic skua {Stercorarius antarcticus} scavenging on dead penguin chick. Antarctica

Tui De Roy / South Polar Skua (Stercorarius maccormicki) pair fighting over Emperor Penguin (Aptenodytes forsteri) chick carcass, Prydz Bay, eastern Antarctica

Tui De Roy / South Polar Skua (Stercorarius maccormicki) bathing, Prydz Bay, eastern Antarctica

Eric Baccega / Lonnberg's skua (Stercorarius antarcticus lonnbergi) in flight, searching for prey, Kerguelen Archipelago, Sub-antarctic, Territory of the French Southern and Antarctic Lands, December 1999

Eric Baccega / Lonnberg's skua (Stercorarius antarcticus lonnbergi) in flight, Kerguelen Archipelago, Sub-antarctic, Territory of the French Southern and Antarctic Lands, December

Eric Baccega / Lonnberg's skua (Stercorarius antarcticus lonnbergi) in flight, Kerguelen Archipelago, Sub-antarctic, Territory of the French Southern and Antarctic Lands, December

Hanne & Jens Eriksen / Antarctic skua resting in grass {Stercorarius antarcticus} South Georgia, December