In British folklore, a single magpie traditionally brings sorrow when seen alone.
The belief is remembered in the counting rhyme beginning “One for sorrow, two for joy.” Its best-known sequence assigns different meanings to groups of magpies, although versions vary by region and over time. The number one is conventionally linked with sorrow, while two is linked with joy.
Magpies became prominent in European folklore partly because of their noticeable behavior, intelligence, bold coloring, and habit of gathering around human settlements. Their reputation is not consistently negative: in some traditions, seeing several magpies is favorable, and in other cultures the bird has positive symbolic associations.
The rhyme is a piece of folklore rather than an observation showing that magpies predict events. A magpie is a member of the crow family, Corvidae. The British tradition concerns counting birds seen together, not identifying a particular species of magpie by its plumage.