A large loss of consciousness in the human race appears to make many crows drop from the sky, dead. This happened in the GBO and in the Ganwar incident. The connection was made by FBI agents Mark Benford and Janis Hawk after Rudolf Geyer gave them a pamphlet about crows after telling his flashforward. The reason for their death during these "blackouts" is yet to be revealed.
In the episode 'A561984' (season 1, episode 10), clips are shown of the Chess Player sitting in his secret lab in Divine Doll Company, while some crows fly by the screen, and several others of them can be seen in the background.
A group of crows is referred to as a "murder."