Having watched the feathered fiends do their thing, I cannot imagine how they were ever stuck with the moniker of “Bluebird of Happiness” except maybe as some sick prank.
They are territorial, much like Lovebirds can be.
The only thing I can point to is that maybe they signal Spring is definitely here.
Before they chase you screaming across a field.
oh no .. a long hot summer coming?
Be careful running across a field or you might step in some congressional speech.