According to something I saw once on PBS, it is because a group of crows would sometimes "murder" a cow.
Don’t know
a group of Blackbirds is called a murder
Blackbirds reproduce by laying eggs.
There is no specific collective noun for blackbirds but any collective noun for birds will do; for example a flight of blackbirds or a flock of blackbirds.
Blackbirds
The collective noun for blackbirds could be either a cloud, flock, grind, or a merl of blackbirds.
a group of Blackbirds is called a murder
Very interesting question. A group of blackbirds is most correctly called either a cloud, a cluster or a merle of blackbirds. Because they are so similar to ravens and crows, they are also called a murder, but this is not the most correct term.
A group of crows is called a murder.
A group of magpies is called a tiding, tribe, charm, gulp, flock, or murder
A group of CROWS is called a murder. A group of crows is called a murder. This is not what they do. They are not birds of prey, although they may eat carrion.
A murder.
A group of crows is called a "murder".
That'd be a murder of crows.
Two or more crows is called a murder of crows.
murder
A Murder is the collective noun for a group of crows and a group of ravens is called a murder of ravens
No it is called a murder or a horde