As the crow flies. The shortest route between two given places. The crow flies straight to its point of destination. Called the bee-line in America.
Crow. (See Raven.)
I must pluck a crow with you; I have a crow to pick with you. I am displeased with you, and must call you to account. I have a small complaint to make against you. In Howell's proverbs (1659) we find the following, “I have a goose to pluck with you,” used in the same sense; and Chaucer has the phrase “Pull a finch, ” but means thereby to cheat or filch. Children of distinction among the Greeks and Romans had birds for their amusement, and in their boyish quarrels used to pluck or pull the feathers out of each other's pets. Tyndarus, in his Captives, alludes to this, but instances it with a lapwing. In hieroglyphics a crow symbolises contention, discord, strife. “If a crow help us in, sirrah, we'll pluck a crow together.” —Shakespeare: Comedy of Errors, iii. 1.
If not, resolve before we go, That you and I must pull a crow.
Butler: Hudibras, part ii. 2.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894