Remember all those observant birds forming their pair bonds on January 22? One species, the common loon, performs an even more impressive calendrical feat:
While our birds [in central Europe] have had to adjust to the new calendar only once, and have moved their wedding date each year ahead to a single, immoveable day, the immer birds [common loons] of Norway can distinguish the fourth Sunday of Advent from any other day, and this is the only day when they can be found on land.
As a result, the Norwegians call that Sunday “Immer Sunday” or “Ommer Sunday.” And the German natural historian Philipp Ludwig Statius Müller was so impressed with the story that he named the loon Colymbus immer, the Advent bird.
Merry Christmas!
