Adult, non-breeding Arctic tern (Sterna paradisaea) on ice in Paradise Bay, Antarctica, Polar Regions

Coastline with headland in the background, at Sterna Bay, Paxos, Ionian Islands, Greek Islands, Greece, Europe

Adult royal tern (Sterna maxima) on the wing in Magdalena Bay on the Pacific side of the Baja Peninsula, Baja California Sur, Mexico.

Adult royal tern (Sterna maxima) on the wing in Magdalena Bay on the Pacific side of the Baja Peninsula, Baja California Sur, Mexico.

Adult Antarctic Tern (Sterna vittata) nesting and mating on Enterprise Island near the wreck of the Gouvernoren, a Norwegian whaler which caught fire and sank in Wilhelmina Bay in 1916, Antarctica.

Adult Antarctic tern (Sterna vittata) in flight in whalers bay, Deception Island, South Shetland Islands, Antarctica, Southern Ocean.

Adult Antarctic Tern (Sterna vittata) nesting and mating on Enterprise Island near the wreck of the Gouvernoren, a Norwegian whaler which caught fire and sank in Wilhelmina Bay in 1916, Antarctica

Juvenile Antarctic tern (Sterna vittata) in flight in whalers bay, Deception Island, South Shetland Islands, Antarctica, Southern Ocean.

Arctic Tern (Sterna paradisaea) on Hudson Bay, Churchill, Manitoba, Canada. Arctic Terns nest commonly in Northern Manitoba, Nunavut, and the Northwest territories. They defend their nests and young very aggressively against all predators and threats including humans.

Arctic Tern (Sterna paradisaea) on Hudson Bay, Churchill, Manitoba, Canada. Arctic Terns nest commonly in Northern Manitoba, Nunavut, and the Northwest territories. They defend their nests and young very aggressively against all predators and threats including humans.

Royal tern (Thalasseus maximus), Courtship ritual, Magdalena Bay (Madelaine Bay), Puerto San Carlos, Baja California Sur, Mexico