pam, I'm struck by the symbolism of this.
5000 dead blackbirds on New Year's Eve in the USA
8000 dead turtleneck doves 7 days later in Italy
The turtledove is a "type" of Christ and it makes me think about the Holy Thorn tree which was cut down in England not so long ago, also symbolic of Christ and Christianity.
I found some stuff about black birds here.
RAVENS, CROWS, BLACKBIRDS
OMEN OF DEATH & DIVINE PROVIDENCE
Uncovering the Myths Surrounding Ravens, Blackbirds, and Crows
Some cultures, like the Egyptians, Romans, and Arabs, have respected the power of these birds while others have feared them. Some have viewed them as symbols of pure evil while others have merely viewed them as omens or prophets.
The Irish once used these birds for divination because they believed that they possessed second sight. It is said that the British believed that ravens fleeing the Tower of London would be an omen of the upcoming fall of the English monarchy.
Writers have, over the years, written about the raven. Many contended that he is the symbol of death. The bird is even mentioned in the Bible; plucking out the eyes of sinners in Proverbs 30:17 and descending upon the wicked in Isaiah 34:11.