An Arctic tern (Sterna paradisaea) is a seabird known for its long migrations. Some key facts about the Arctic tern include:

• Appearance: They are medium-sized birds with a white body, grey wings, a black cap, and a red bill and feet.
• Habitat: They breed in the Arctic and subarctic regions of Europe, Asia, and North America.
• Migration: Arctic terns are famous for their exceptionally long migrations, flying from their Arctic breeding grounds to Antarctica and back each year. This gives them the longest known migration of any animal.
• Diet: They primarily eat fish and small invertebrates, which they catch by diving into the water.
• Lifespan: They have a relatively long lifespan for birds, often living 15-30 years.

For more information, you can check these resources:

• All About Birds - Arctic Tern
• National Geographic - Arctic Tern