This is the seventh in my series for The Twelve Days of Christmas. Swans were protected in medieval England and considered part of the royal estate. They were once considered a tasty bird for the dinner table, in keeping with many of the earlier birds in the song, and though they are no longer on the menu, swan upping still takes place once a year on the River Thames, where cygnets are weighed and swans are checked for health.  The red-liveried Swan Uppers operate as part of a royal charter which has been in practice since the 12th century.