According to something I saw once on PBS, it is because a group of crows would sometimes "murder" a cow.
a group of Blackbirds is called a murder
A group of blackbirds is commonly called a "murmuration." This term is often used to describe the swirling, coordinated flight patterns of flocks of birds, particularly during their aerial displays. Additionally, the term "flock" can also be used generically for any group of birds.
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
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.
That'd be a murder of crows.
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".
Two or more crows is called a murder of crows.
murder
No it is called a murder or a horde
A Murder is the collective noun for a group of crows and a group of ravens is called a murder of ravens