As the crow flies

The expression as the crow flies is an idiom for the most direct path between two points.

[1][2] The meaning of the expression is attested from the early 19th century, and appeared in the Charles Dickens novel Oliver Twist (1838):[1][2] "We cut over the fields at the back with him between us – straight as the crow flies – through hedge and ditch.

[3] While crows do not swoop in the air like swallows or starlings, they often circle above their nests.

[3] One suggested origin of the term is that before modern navigational methods were introduced, cages of crows were kept upon ships and a bird would be released from the crow's nest when required to assist navigation, in the hope that it would fly directly towards land.

[1] However, the earliest recorded uses of the term are not nautical in nature, and the crow's nest of a ship is thought to derive from its shape and position rather than its use as a platform for releasing crows.