The origin of the term ‘murder’ meaning a flock of crows has much to do with the scavenging nature of this and other corvids. Historically the presence of the gallows and slaughter on the battlefields would have provided rich pickings for our two species of crow. Such an association with death saw the development of folklore and superstition, causing the birds to be viewed less than favourably.
In fact some of this mythology was originally associated with ravens but, given the considerable difficulties that many people have in identifying black corvids, it is understandable that traditions were transferred between the species.
Much of the folklore is rather macabre. There is, for example, the belief that crows peck out the eyes of their ‘victims’ to attain their excellent vision. It is a small step to see a group of crows, attracted to a corpse, not as scavengers but as agents of death with murderous intentions.