The tradition of hunting the wren is performed in Ireland, the Isle of Man, some places in Wales and other locations in Europe on December 26th (Boxing Day or St. Stephen's Day). A wren, either live or fake, is caught and paraded around the village by "wrenboys" begging for pennies. The custom is derived from ancient customs of sacrificing the King for the Year at the winter solstice to usher in the new year. These rituals are discussed in Sir James George Frazer's book The Golden Bough: A Study in Magic and Religion.
Recorded by the Clancy Brothers and others.
This is the same melody as "Green Bushes" and was used by Ralph Vaughan Williams, along with "My Bonny Bonny Boy" in the Intermezzo movement of The English Folksong Suite.