Arctic tern

Bird that breeds in the Arctic and subarctic and migrates to the Antarctic

The Arctic tern (Sterna paradisaea) is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and subarctic regions of Europe (as far south as Brittany), Asia, and North America (as far south as Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later.

From Wikipedia, under CC BY-SA. More on occurri.